Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (2,977)
  • 1990-1994  (8,563)
  • Analytical Chemistry and Spectroscopy  (9,750)
  • Genetics  (1,790)
Source
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Mitochondrial DNA mutation at np 3243 in a family with maternally inherited diabetes mellitus (1999)
    Springer
    Acta diabetologica 36 (1999), S. 163-167 
    Details
    ISSN: 1432-5233
    Keywords: Key words Mitochondrial DNA ; Genetics ; Maternally inherited diabetes mellitus ; Deafness ; np 3243 mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Mitochondrial DNA (mtDNA) gene defects may play a role in the development of maternally inherited diabetes mellitus and deafness (MIDD). A family from Southern Italy who showed maternal transmission of type 2 diabetes mellitus with three individuals affected is described. A 10.4 kb deletion and mutations at nucleotide positions (np) 3243, 7445 and 11778 in the mtDNA of six relatives were sought. The mitochondrial np 3243 mutation of the tRNA Leu (UUR) gene was identified in a boy affected by optic atrophy and mental retardation, as well as in his diabetic mother. No other mutations or deletions were found. Our study points out the variable phenotypic expression of the np 3243 mtDNA mutation. This may suggest the presence of other mitochondrial or nuclear mutations required to modulate the phenotype. A clinical and metabolic follow-up of all family members was necessary to understand the role of the np 3243 mutation, especially in one child affected by optic atrophy and mental retardation. Further studies will be aimed at investigating the prevalence of mutations and deletions of mtDNA in type 2 diabetes mellitus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005920050161
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    AC/GT and AG/CT microsatellite repeats in peach [Prunus persica (L) Batsch]: isolation, characterisation and cross-species amplification in Prunus (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 65-72 
    Details
    ISSN: 1432-2242
    Keywords: Key words Simple sequence repeat (SSR) ; Microsatellites ; Molecular markers ; Genetics ; Fingerprinting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We report the sequences of 17 primer pairs of microsatellite loci, which we have cloned and sequenced from two genomic libraries of peach [Prunus persica (L) Batsch] ‘Redhaven’, enriched for AC/GT and AG/CT repeats respectively. For ten of these microsatellite loci we were able to demonstrate Mendelian inheritance in a segregating back-cross population; the remainder did not segregate. The polymorphism of the microsatellites was evaluated in a panel of ten peach genotypes, including true-to-type peaches, nectarines and one canning-peach. Fifteen microsatellites (88%) were polymorphic showing 2–4 alleles each. The mean heterozygosity, averaged over all loci, was 0.32 and significantly higher than that reported in the literature for isozymes and molecular markers, such as RFLPs and RAPDs. We have also assayed the cross-species transportability and found that ten microsatellite (59%) gave apparently correct amplification in all Prunus species surveyed, namely P. domestica (European plum), P. salicina (Japanese plum), P. armeniaca (apricot), P. dulcis (almond), P. persica var. vulgaris (peach), P. persica var. laevis (nectarine), P. avium (sweet cherry) and P. cerasus (sour cherry), with three of them also being amplified in Malus (apple). The remaining microsatellites gave less-extensive amplification. Because of their appreciable polymorphism and wide cross-species transportability, most of these new markers can be integrated into the linkage maps which are currently being constructed in peach, as well as in other stone fruit crops, such as almond, apricot, cherry and plum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Pathologie der Rhabdo- myosarkome des Kindes- und Adoleszentenalters Ein Bericht des Kindertumorregisters bei der Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH) (1999)
    Springer
    Der Pathologe 20 (1999), S. 87-97 
    Details
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Rhadomyosarkom ; Klassifizierung ; Immunhistochemie ; Genetik ; Prognose ; Key words Rhabdomyosarcoma ; Classification ; Immunohistochemistry ; Genetics ; Prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Rhabdomyosarcoma (RMS) is the most important and a very heterogeneous group of malignant soft tissue tumors of childhood and adolescence.The two major subtypes (embryonal and alveolar) share a common myogenic differentiation, but seem to be histogenetically not related. The so-called ’International Classification of Rhabdomyosarcoma’ includes, besides the two major subtypes, the botryoid and leiomyomatous subtypes of embryonal RMS which are associated with a better prognosis and are treated less aggressively according to current protocols. In addition, the solid variant of alveolar RMS is included in the alveolar group of RMS. The identification of the various subtypes is necessary and important because the treatment with the current protocols is also related to histology. Using conventional stains and immunohistochemistry, these subtypes are distinguishable. Genetic analysis can be helpful in the demonstration of t(2;13) or t(1;13) translocations in alveolar RMS. The identification of alveolar RMS with t(1;13) translocation might become important in the future, because this type of translocation seems to be related to a better prognosis as compared to tumors with a t(2;13) translocation.
    Notes: Zusammenfassung Rhabdomyosarkome stellen eine heterogene Gruppe von ganz verschiedenartigen, histogenetisch wohl nicht zusammengehörenden Tumoren dar. Nach der heute verwendeten „Internationalen Klassifikation” der Rhabdomyosarkome werden neben der Unterteilung in embryonalen und alveoläre Rhabdomyossarkome auch Subtypen des embryonalen RMS identifiziert (botryoider und leiomyomatöser Subtyp), die durch eine günstigere Prognose und durch die Notwendigkeit einer weniger aggressive Therapie gekennzeichnet sind. Durch Einsatz von verschiedenen histologischen und immunhistochemischen Färbungen ist die Identifizierung der verschiedenen Typen der RMS heute möglich und auch zwingend notwendig, da die einzelnen Entitäten nach ganz unterschiedlichen Therapieprotokollen behandelt werden. Der Nachweis typischer molekulargenetischer Veränderungen kann in der Unterscheidung insbesondere von embryonalen und alveolären RMS hilfreich sein. In der Regel ist die Abgrenzung zwischen diesen beiden Entitäten auch an konventionell gefärbten Schnittpräparaten möglich. Die Identifizierung von alveolären RMS mit einer t(1;13)-Translokation könnte in Zukunft eine große Bedeutung haben, da diese genetische Veränderung möglicherweise mit einer günstigeren Prognose assoziert sein könnte als die t(2;13)-Translokation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002920050326
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Etiology of the inflammatory bowel diseases (1999)
    Springer
    International journal of colorectal disease 14 (1999), S. 2-9 
    Details
    ISSN: 1432-1262
    Keywords: Key words Inflammatory bowel disease ; Crohn's disease ; Ulcerative colitis ; Epidemiology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Inflammatory bowel diseases (IBD) are complex disorders. While the exact etiology of these diseases remains unknown, recent progress in the epidemiology and genetics of IBD has clearly demonstrated both environmental and genetic factors to play a role in the development of the disease, and it is expected that some risk factors are common for both Crohn's disease (CD) and ulcerative colitis (UC). The environmental factor(s) are associated with the Western way of life in the second half of the twentieth century. Cigarette smoking is presently the best known environmental factor. However, the effect of tobacco is opposite in CD and UC. A familial history of IBD is the most important risk factor for developing the disease, suggesting a genetic predisposition to IBD. This hypothesis has recently been confirmed by the localization of at least two susceptibility loci on chromosomes 12 and 16. These genes seem to play a role in both CD and UC. They must now to be identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003840050175
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Genetik schizophrener Störungen Neuere Konzepte und Befunde (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 955-969 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Schizophrenie ; Genetik ; Schizophrenes Spektrum ; Kopplungsuntersuchungen ; Assoziationsuntersuchungen ; Key words Schizophrenia ; Genetics ; Schizophrenia spectrum ; Linkage studies ; Association studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Schizophrenia is a genetic complex disease as it does not follow monogenic transmission while non-familial environmental factors have a strong additional impact. A heterogenous, continuous phenotype is transmitted in families which can now be more precisely characterized. Genes coding for proteins with presumed pathophysiological relevance are apparently not playing a major causal role. However, in the last three years several (currently seven) candidate regions have been identified in a replicable manner by linkage studies. These regions are likely to host susceptibility genes for schizophrenia, but none of them has been identified up to now. Given these findings, polygenic transmission has now become very likely. The candidate regions are currently being narrowed down by various promising techniques.
    Notes: Zusammenfassung Die Schizophrenie gehört zu den genetisch komplexen Erkrankungen, die keinem monogenen Erbgang folgen und bei denen auch nichtfamiliäre Umgebungsfaktoren eine wichtige Rolle spielen. Dabei wird intrafamiliär ein heterogener, quantitativ variierender Phänotyp übertragen, der zunehmend genauer charakterisiert werden kann. Keines der bekannten Gene mit vermuteter pathophysiologischer Relevanz spielt nach den bisherigen Erkenntnissen eine substantielle Rolle. In den vergangenen drei Jahren ist es aber erstmals durch Kopplungsuntersuchungen gelungen, mehrere replizierbare Kandidatenregionen (derzeit sieben) auf dem Genom zu identifizieren, in denen vermutlich Suszeptibilitätsgene für Schizophrenie liegen. Keines dieser Gene wurde jedoch bislang identifiziert. Mit diesen Befunden ist eine polygene Übertragung der Schizophrenie sehr wahrscheinlich geworden. Verschiedene Techniken zur Eingrenzung der Kandidatenregionen werden derzeit erfolgreich angewandt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050524
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    A mutation at codon 279 (N279K) in exon 10 of the Tau gene causes a tauopathy with dementia and supranuclear palsy (1999)
    Springer
    Acta neuropathologica 98 (1999), S. 62-77 
    Details
    ISSN: 1432-0533
    Keywords: Key words Frontotemporal dementia ; Genetics ; Progressive supranuclear palsy ; Tauopathy ; Exon ; amplifcation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Recently intronic and exonic mutations in the Tau gene have been found to be associated with familial neurodegenerative syndromes characterized not only by a predominantly frontotemporal dementia but also by the presence of neurological signs consistent with the dysfunction of multiple subcortical neuronal circuitries. Among families, the symptomatology appears to vary in quality and severity in relation to the specific Tau gene mutation and often may include parkinsonism, supranuclear palsies, and/or myoclonus, in addition to dementia. We carried out molecular genetic and neuropathological studies on two patients from a French family presenting, early in their fifth decade, a cognitive impairment and supranuclear palsy followed by an akinetic rigid syndrome and dementia. The proband died severely demented 7 years after the onset of the symptoms; currently, his brother is still alive although his disease is progressing. In both patients, we found a Tau gene mutation in exon 10 at codon 279, resulting in an asparagine to lysine substitution (N279K). Neuropathologically, widespread neuronal and glial tau accumulation in the cortex, basal ganglia, brain stem nuclei as well as in the white matter were the hallmark of the disease. These deposits were shown by immunohistochemistry and immunoelectron microscopy, using a battery of antibodies to phosphorylation-dependent and phosphorylation-independent epitopes present in multiple tau regions. In the neocortex, tau-immunopositive glial cells were more numerous than immunopositive neurons; the deeper cortical layers as well as the white matter adjacent to the cortex contained the largest amount of immunolabeled glial cells. In contrast, some brain stem nuclei contained more neurons with tau deposits than immunolabeled glial cells. The correlation of clinical, neuropathological and molecular genetic findings emphasize the phenotypic heterogeneitiy of diseases caused by Tau gene mutations. Furthermore, to test the effect of the N279K mutation and compare it with the effect of the P301L exon 10 mutation on alternative splicing of Tau exon 10, we used an exon amplification assay. Our results suggest that the N279K mutation affects splicing similar to the intronic mutations, allowing exon 10 to be incorporated more frequently in the Tau transcript.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051052
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Analysis of potential phosphorylation sites in human T cell leukemia virus type 1 Tax (1999)
    Springer
    Journal of biomedical science 6 (1999), S. 206-212 
    Details
    ISSN: 1423-0127
    Keywords: Tax ; HTLV-1 ; Trans-activation ; Phosphorylation ; Mutagenesis ; Transcription ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The human T cell leukemia virus type 1 (HTLV-1) Tax is a phosphoprotein, however, the contribution of phosphorylation to Tax activity is unknown. Previous studies have shown that phosphorylation of Tax occurs on serine residue(s), within one tryptic fragment, in response to 4β-phorbol-12β-myristate-13α-acetate, in both mouse and human cells. Studies were conducted in multiple cell lines to identify the specific phosphorylated serines as a prelude to functional analysis. The phosphorylation pattern of Tax was found to be different in 293T and COS-7 cells in comparison with MT-4 and Px-1 cells. However, one tryptic fragment remained consistent in comigration analyses among all cell lines. Using selected Tax serine mutants a tryptic fragment containing a serine at residue 113 believed to be the site of phosphorylation of Tax did not comigrate with the common phosphorylated tryptic fragment. Analysis of selected Tax mutants for ability totrans-activate the cytomegalovirus promoter demonstrated mutation of serine 77 to alanine reducedtrans-activation by 90% compared to wild-type Tax. However, examination of the phosphorylation pattern of the serine 77 mutant demonstrated that it is not the site of phosphorylation. These studies demonstrate the importance of using relevant cell lines to characterize the role of phosphorylation in protein function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02255904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Controlling septation in fission yeast: finding the middle, and timing it right (1999)
    Springer
    Current genetics 35 (1999), S. 571-584 
    Details
    ISSN: 1432-0983
    Keywords: Key words Cytokinesis ; Kinase ; Mitosis ; Schizosaccharomyces pombe ; Cell division ; Phosphatase ; Mutant ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002940050455
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Clinical relevance of monosomy 22q11.2 in children with pulmonary atresia and ventricular septal defect (1999)
    Springer
    European journal of pediatrics 158 (1999), S. 302-307 
    Details
    ISSN: 1432-1076
    Keywords: Key words Congenital heart disease ; Pulmonary atresia and ventricular septal defect ; Genetics ; Monosomy 22q11.2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of our study was to describe the prevalence and the clinical spectrum of monosomy 22q11.2 in a population of patients with pulmonary atresia and ventricular septal defect. We examined all 44 patients with this conotruncal cardiac malformation who presented to our institution from January 1994 until December 1997. The type of collateral lung perfusion was recorded including anomalies of the pulmonary arteries as well as facial and immunological abnormalities. Molecular-cytogenetic testing for a 22q11.2 microdeletion was performed using the probes D22S75 and cHKAD26. Statistical differences were evaluated with the Fisher's Exact Test. Monosomy 22q11.2 was present in ten children (23%) with major aortopulmonary collateral arteries (group 1). The remaining 13 children (29%) with major aortopulmonary collateral arteries (group 2) and all 21 children (48%) with ductus arteriosus (group 3) were negative for this microdeletion. All children in group 1 had facial anomalies, six had mild immunological abnormalities including decreased CD 4+ or CD 8+ cells. Anomalies of the pulmonary vascular bed were significantly more frequent in children of group 1 (9/10) than in children of group 2 (4/13) or group 3 (0/21). Due to these pulmonary vascular anomalies, corrective surgery had been accomplished in fewer children with monosomy 22q11.2 (none in group 1) as compared to 7/13 children in group 2 and 14/21 children in group 3. Conclusion In children with pulmonary atresia and ventricular septal defect, monosomy 22q11.2 is preferentially associated with major aortopulmonary collateral arteries. Due to the higher incidence of pulmonary arterial abnormalities, successful surgical repair will require a different therapeutic approach in most patients with this microdeletion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310051077
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Linkage analysis of candidate myelin genes in familial multiple sclerosis (1999)
    Springer
    Neurogenetics 2 (1999), S. 155-162 
    Details
    ISSN: 1364-6753
    Keywords: Key words Multiple sclerosis ; Genetics ; Myelin basic protein ; Myelin oligodendrocyte glycoprotein ; Proteolipid protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: ABSTRACT Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system. A complex genetic etiology is thought to underlie susceptibility to this disease. The present study was designed to analyze whether differences in genes that encode myelin proteins influence susceptibility to MS. We performed linkage analysis of MS to markers in chromosomal regions that include the genes encoding myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMGP), and myelin oligodendrocyte glycoprotein (MOG) in a well-characterized population of 65 multiplex MS families consisting of 399 total individuals, 169 affected with MS and 102 affected sibpairs. Physical mapping data permitted placement of MAG and PLP genes on the Genethon genetic map; all other genes were mapped on the Genethon genetic map by linkage analysis. For each gene, at least one marker within the gene and/or two tightly linked flanking markers were analyzed. Marker data analysis employed a combination of genetic trait model-dependent (parametric) and model-independent linkage methods. Results indicate that MAG, MBP, OMGP, and PLP genes do not have a significant genetic effect on susceptibility to MS in this population. As MOG resides within the MHC, a potential role of the MOG gene could not be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100480050076
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Management of mantle cell lymphoma (1999)
    Springer
    Annals of hematology 78 (1999), S. 485-494 
    Details
    ISSN: 1432-0584
    Keywords: Key words Mantle cell lymphoma ; Classification ; Pathology ; Prognosis ; Immunology ; Genetics ; Antineoplastic agents ; Combined ; Therapeutic use ; Radiotherapy ; Hematopoietic stem cell transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002770050545
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Why is acute leukemia more common in males? A possible sex-determined risk linked to the ABO blood group genes (1999)
    Springer
    Annals of hematology 78 (1999), S. 233-236 
    Details
    ISSN: 1432-0584
    Keywords: Key words Acute leukemia ; Genetics ; Sex ; ABO Blood group
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Acute leukemia is more common in males at almost every age, and this fact remains unexplained. A study was carried out in northeast peninsular Malaysia, where the population is predominantly Malay, to examine whether there was a difference in ABO blood group distribution between males and females with acute leukemia (AL). The ABO blood groups of 109 male and 79 female patients with AL (98 ALL, 90 AML) were compared with those of 1019 controls. In the control population, 39.7% were group O. Among males with AL, 39.4% were group O, whereas among females with AL, the proportion was 24.1% (p=0.03). The same trend to a lower proportion of group O among females was seen if the group was divided into adult/pediatric or lymphoblastic/myeloblastic groups, though these differences were not statistically significant. If these findings can be confirmed, they suggest the presence of a "sex-responsive" gene near to the ABO gene locus on chromosome 9, which relatively protects group O women against AL, at least in our population. The existence of such a gene might also partly explain why acute leukemia, and possibly other childhood cancers, are more common in males.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002770050507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    The neurofibromatoses. An overview (1999)
    Springer
    Italian journal of neurological sciences 20 (1999), S. 89-108 
    Details
    ISSN: 1126-5442
    Keywords: Key words Neurofibromatosis ; Nf1 ; Nf2 ; Mosaic/segmental neurofibromatosis ; Variants ; Classification ; Neurological manifestations ; Genetics ; Childhood ; Adulthood
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The last two decades have seen clinical and molecular delineation of the different forms of neurofibromatosis. Differentiation of these forms is not just an academic exercise: their natural history, management and genetic counselling are quite different. Of the numerical classifications of neurofibromatosis proposed in the past, only neurofibromatosis type 1 (Nf1) and neurofibromatosis type 2 (Nf2) are now well delineated clinically and have been shown to be distinct at the molecular level. For both forms of neurofibromatosis, patients with clinical generalised disease have been demonstrated to be mosaic at the molecular level, and features of segmental or mosaic Nf1 and Nf2 have been delineated. Other reported forms of neurofibromatosis are rarer; they include Watson syndrome, hereditary spinal neurofibromatosis, familial intestinal neurofibromatosis, autosomal dominant café-au-lait spots alone, autosomal dominant neurofibromas alone, and schwannomatosis, the latter believed to be a variant of Nf2. Further delineation is neeeded for individuals having overlapping features of Noonan's syndrome and neurofibromatosis (the so-called Noonan/neurofibromatosis syndrome) and the syndrome of “multiple naevi, multiple schwannomas and multiple vaginal leiomyomas”. In this article we review the forms of neurofibromatosis which we believe are true clinical entities. Particular attention is given to the neurological manifestations of neurofibromatosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100720050017
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Insulin resistance and impaired insulin secretion due to phosphofructo-1-kinase-deficiency in humans (1999)
    Springer
    Journal of molecular medicine 77 (1999), S. 96-103 
    Details
    ISSN: 1432-1440
    Keywords: Key words Diabetes ; Genetics ; Phosphofructokinase ; Glycogenosis ; NIDDM ; PFK
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The etiology of non-insulin-dependent diabetes mellitus (NIDDM) is usually explained as a combination of peripheral insulin resistance and impaired beta-cell function. Phosphofructo-1-kinase (PFK1) is a rate limiting enzyme in glycolysis, and its muscle subtype (PFK1-M) deficiency leads to an autosomal recessively inherited disorder known as glycogenosis type VII or Tarui’s disease. It was evaluated whether PFK1-M deficiency leads to NIDDM in humans. A core family of four was evaluated for PFK1-M deficiency by DNA- and enzyme-activity-analyses. All members underwent oral and intravenous glucose tolerance test (oGTT/ivgtt), as well as an insulin sensitivity test (IST) using octreotide. Results: Father (46 years, BMI 22.4 kg/m2) and older son (19 years, BMI 17.8 kg/m5) showed homozygous PFK1-M deficiency, while mother (47 years, BMI 28.4 kg/m5) and younger son (13 years, BMI 16.5 kg/m5) were shown to be heterozygously PFK1-M-deficient on enzyme activity levels. DNA analysis revealed an exon 5-missense-mutation at one allele of all four members, and an exon 22-frameshift-mutation at the other allele of the two homozygously affected individuals. By oGTT the father showed impaired glucose tolerance, and the mother clinical diabetes. By ivGTT both parents and the older son had a decreased first phase insulin secretion, and a diminished glucose disappearance rate. The IST showed marked insulin resistance in both parents and the older son, and moderate resistance in the younger son, previously not described. Conclusion: PFK1-M-deficiency leads to a metabolic state typical for early NIDDM in homozygously affected humans, especially concerning insulin resistance and loss of first phase beta-cell insulin secretion, and may contribute to the manifestation of NIDDM in a subgroup of patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001090050311
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Polymorphisms in the glutamate transporter gene EAAT2 in European ALS patients (1999)
    Springer
    Journal of neurology 246 (1999), S. 1140-1144 
    Details
    ISSN: 1432-1459
    Keywords: Key words Amyotrophic lateral sclerosis ; Genetics ; Glutamate transporter gene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurological disorder characterised by degeneration of upper and lower motor neurons. Whilst the primary pathogenic trigger is unknown in most cases, evidence is mounting to implicate a role for glutamate-mediated neurotoxicity in the disorder. Recent studies have shown reduced levels of the mainly astroglial glutamate transporter EAAT2 in ALS motor cortex and spinal cord and multiple abnormal EAAT2 mRNA species in ALS brain tissue. One cause of the low EAAT2 levels may be that point mutations in the EAAT2 gene, EAAT2, result in an abnormal unstable protein. To test this hypothesis we analysed EAAT2 in 128 sporadic and 23 familial European ALS cases. No variants within the coding sequence of EAAT2 to affect the protein sequence nor in the consensus splice sites of the flanking intronic sequences were found in any cases, similar to findings in other reports. Frequent polymorphisms within the flanking intronic sequences of both exons 2 and 4 were seen but at similar frequencies in controls. Mechanisms other than mutations within the coding region of EAAT2 must therefore be responsible for the low levels of EAAT2 seen in most cases of ALS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050532
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Early diagnosis and the clinical genetics of Alzheimer’s disease (1999)
    Springer
    Journal of neurology 246 (1999), S. 69-72 
    Details
    ISSN: 1432-1459
    Keywords: Key words Alzheimer’s disease ; Genetics ; Genetic counseling ; Predictive testing ; Diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alzheimer’s disease (AD) has a significant genetic background manifested as autosomal dominant inheritance in some early-onset families and as familial risk in late-onset cases. Three genes responsible for early-onset autosomal dominant AD have been identified, and one gene, apolipoprotein E, has been confirmed as a susceptibility gene for late-onset forms of the disorder. These findings raise the possibility of genetic testing, either for early diagnosis or prediction. For early-onset autosomal dominant AD genetic testing will have a limited but useful role in confirming diagnosis in established cases and in predictive counselling for relatives; a situation analogous to that for Huntington’s disease. For late-onset AD significant problems remain to be overcome before the advances in molecular genetics have a direct clinical application
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004150050310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Self-incompatibility in passion fruit: evidence of two locus genetic control (1999)
    Springer
    Theoretical and applied genetics 98 (1999), S. 564-568 
    Details
    ISSN: 1432-2242
    Keywords: Key words Passiflora ; Self-incompatibility ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The self-incompatibility in yellow passion fruit was previously described as homomorphic sporophytic with monofactorial inheritance. Five progenies were obtained by bud-selfing. The plants of these progenies were selfed, reciprocally crossed within each progeny and crossed with known incompatible phenotypes to identify their phenotypic group. Fruit set was evaluated at the 7th day after pollination. Two progenies consisted of two self-incompatible groups, the other three formed three suck groups. The groups were identified as S1, S2, S3, S4, S5 and S6. The results provide evidence that the self-incompatibility of passion fruit is controlled by two loci, the S-gene and another, whose expression needs to be investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    A stylar ribonuclease assay to detect self-compatible seedlings in almond progenies (1999)
    Springer
    Theoretical and applied genetics 99 (1999), S. 800-810 
    Details
    ISSN: 1432-2242
    Keywords: Key words Almond ; Compatibility ; Genetics ; Prunus dulcis ; Ribonucleases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Six almond progenies, each the product of a cross between a self-compatible and a self-incompatible parent, were analysed for stylar ribonucleases. Proteins were extracted and separated using non-equilibrium pH gradient electrofocusing (NEPHGE), and the gels were stained for ribonuclease activity. Most seedlings showed either two principal bands, interpreted as corresponding to two incompatibility alleles, or a single band. The seedlings were also bagged in the field at flowering time to determine fruit set after selfing, and some were also examined for the growth of pollen-tubes in selfed styles using UV fluorescence microscopy. With very few exceptions, those seedlings showing single-banded zymograms were found to be self-compatible according to field and microscope studies, and those with two bands were found to be self-incompatible. We conclude that the allele for self-compatibility in almond does not code for ribonuclease activity and that the ribonuclease isoenzyme assay is a convenient technique for predicting self-compatibility in segregating progenies. A novel band in two derivatives of ’Ferrastar’ was ascribed to a new incompatibility allele, S 10 .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001220051299
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Craniosynostosis: from a clinical description to an understanding of bone formation of the skull (1999)
    Springer
    Child's nervous system 15 (1999), S. 676-680 
    Details
    ISSN: 1433-0350
    Keywords: Key words Craniosynostosis ; Genetics ; FGFR ; Msx2 ; Development ; Skull
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The genetic studies of syndromic craniosynostoses lead to the characterisation of genes that regulate the correct development of the bones of the skull. From these studies, it appears that FGF/FGFR signalling has a crucial role in this problem. Numerous mutations affecting the genes coding for FGFR1, 2 or 3 are responsible for these syndromes. It is interesting to note that some identical mutations produced various different phenotypes, suggesting that other genes modulate the phenotypic expressivity. The other involved genes in these syndromes code for such proteins as Msx2 or Twist that interact in the cellular pathways responsible for FGF action. From these genetic studies, it is now important to establish the role of these proteins during the development of the skull. Msx2 plays a repressive role in osteogenesis, whereas FGFRs act as promoting proteins. In the near future, it will be very important to improve our understanding of these phenomena in order to test specific treatments to prevent the development of such syndromes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003810050457
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Division of labor in a dynamic environment: response by honeybees (Apis mellifera) to graded changes in colony pollen stores (1999)
    Springer
    Behavioral ecology and sociobiology 46 (1999), S. 171-179 
    Details
    ISSN: 1432-0762
    Keywords: Key words Honeybee ; Apis mellifera ; Division of labor ; Genetics ; Pollen foraging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  A fundamental requirement of task regulation in social groups is that it must allow colony flexibility. We tested assumptions of three task regulation models for how honeybee colonies respond to graded changes in need for a specific task, pollen foraging. We gradually changed colony pollen stores and measured behavioral and genotypic changes in the foraging population. Colonies did not respond in a graded manner, but in six of seven cases showed a stepwise change in foraging activity as pollen storage levels moved beyond a set point. Changes in colony performance resulted from changes in recruitment of new foragers to pollen collection, rather than from changes in individual foraging effort. Where we were able to track genotypic variation, increases in pollen foraging were accompanied by a corresponding increase in the genotypic diversity of pollen foragers. Our data support previous findings that genotypic variation plays an important role in task regulation. However, the stepwise change in colony behavior suggests that colony foraging flexibility is best explained by an integrated model incorporating genotypic variation in task choice, but in which colony response is amplified by social interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Erbliche Ursachen und Risikofaktoren der Alzheimer-Krankheit (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 195-205 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Alzheimer-Krankheit ; Genetik ; Risikofaktoren ; Genetische Beratung ; Key words Alzheimer’s disease ; Genetics ; Risk factors ; Genetic counseling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A multifactorial etiology underlies the majority of cases of Alzheimer’s disease (AD). Both ill-defined environmental and genetic factors contribute to the development of the disease. Allele ɛ4 of ApoE is a genetic risk factor. Its presence increases the risk of developing AD. However, presence of e4 is neither necessary nor sufficient for the disease to arise. Apart from the common multifactorial forms of the disease, there are rare variants which are inherited as Mendelian traits. To date three genes are known that can be mutated in these rare forms of AD. Of these, mutations in the gene presenilin 1 on chromosome 14 are most frequent. In addition, mutations in the gene presenilin 2 on chromosome 1 and in the amyloid precursor protein gene (APP on chromosome 21) occur in autosomal dominant AD. This article reviews our present knowledge of the genetics of AD and discusses its relevance for patients with AD and their relatives.
    Notes: Zusammenfassung Der Großteil der Fälle von Alzheimer-Krankheit (AK) hat eine multifaktorielle Ätiologie. Das bedeutet, bisher nicht genauer bekannte Umwelteinflüsse und genetische Faktoren spielen bei der Entwicklung der Krankheit eine wesentliche Rolle. Von seiten der Genetik unterscheidet man bei der AK gegenwärtig genetische Risikofaktroren und Mutationen. Der einzige bisher gesicherte genetische Risikofaktor ist das Allel ɛ4 des Gens für Apolipoprotein E auf Chromosom 19. Dieses Allel erhöht die Wahrscheinlichkeit, an der AK zu erkranken, ist jedoch weder eine notwendige noch eine hinreichende Bedingung. Neben den häufigen Formen mit multifaktorieller Ätiologie kommen seltene Varianten der Krankheit vor, die nach Mendelschen Regeln vererbt werden. Bisher sind 3 Gene bekannt, die bei diesen seltenen, in der Regel früh auftretenden und autosomal dominant vererbten Formen mutiert sein können. Am häufigsten findet sich bei den autosomal-dominanten Fällen eine Mutation im Gen präsenilin 1 auf Chromosom 14, seltener liegen Mutationen im Gen präsenilin 2 auf Chromosom 1 und im Gen des Amyloid- Vorläuferproteins auf Chromosom 21 vor. In diesem Beitrag geben wir eine Übersicht über gegenwärtige Befunde zur Genetik der AK und diskutieren die Bedeutung dieses Wissens für Patienten und deren Verwandte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050423
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Composition and Microstructure Determination of the Syndiotactic Copolymer of para-Methylstyrene and Styrene by Pyrolysis Gas Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 11-16 
    Details
    ISSN: 0935-6304
    Keywords: Pyrolysis gas chromatography ; microstructure determination ; syndiotactic copolymers ; styrenes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The composition and microstructure of syndiotactic para-methylstyrene/styrene copolymer was determined by a pyrolysis gas chromatography (Py-GC) method. This method uses the styrene and para-methylstyrene monomer peak intensities to determine the styrene and para-methylstyrene composition in the copolymer. The number average sequence length of styrene was calculated by using the triad peak intensities. Because of the low concentration of para-methylstyrene in the copolymer, the number average sequence length of para-methylstyrene was determined with formulas that incorporate the copolymer composition and the number average sequence length of styrene. The distribution of para-methylstyrene defined by the terms “percent of single units” and “percent of desired distribution” was calculated by the number average sequence of para-methylstyrene. This method has been tested with copolymers containing up to 24 mole% of para-methylstyrene. The composition results from Py-GC of para-methylstyrene and styrene copolymers used in this study were in excellent agreement with 1H-NMR results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 23
    Electronic Resource
    Electronic Resource
    Superior ECD Performance through Design and Application (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 24-28 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; ECD ; Micro-ECD ; GC detector ; organochlorine pesticides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A new ECD, the HP 6890 Series Micro-ECD, was designed to address inherent deficiencies in classical electron capture detectors (ECD), especially with respect to sensitivity, linearity, dynamic range, and ruggedness. Several novel technologies were incorporated in the totally new design and were refined through practical testing and user feedback. Validation of the micro-ECD performance was accomplished through side-by-side testing of the Micro-ECD with previous ECDs following US EPA Contract Laboratory Program methods for pesticides and PCBs. In addition, extensive interviews were conducted with early users of the Micro-ECD who also had experience with other designs running a variety of ECD methods. The design and resulting performance improvements are described.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 24
    Electronic Resource
    Electronic Resource
    Experimentation with Chiral CE: The Application of Two Chiral Selectors and Partial Filling with Chiral Selector (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 33-38 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrophoresis ; chiral separation ; negatively charged chiral selectors ; capillary filling methods ; dual systems ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Data on the use of two chiral selectors, namely 18-crown-6 tetracarboxylic acid and a negatively charged cyclodextrin derivative (sulfated-β-cyclodextrin or carboxymethyl-β-cyclodextrin), in the same background electrolyte are presented. The use of such dual systems has a considerable influence on the resolution, as illustrated for the separation of tryptophan derivatives. Reduction of the consumption of chiral selector without significant loss in resolution was obtained by only partly filling the capillary and applying a run buffer without selector. This is illustrated for the chiral separation of tryptophan hydroxamate and the diastereomeric and enantiomeric separation of the dipeptide α/b-AspPhe-OMe.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 25
    Electronic Resource
    Electronic Resource
    Determination of Free Diterpenes in Green and Roasted Coffees (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 43-46 
    Details
    ISSN: 0935-6304
    Keywords: Green and roasted coffee ; diterpenes ; cafestol ; kahweol ; 16-O-methylcafestol ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The three coffee diterpenes cafestol, kahweol, and 16-O-methylcafestol are mostly esterified with fatty acids. Little has been published about the diterpenes occurring in the free form. By means of gel permeation chromatography on Bio Beads S-X3, it is now possible to simultaneously analyze and quantify the small amounts of these compounds by RP-HPLC. In this way, free kahweol was first proved to be an ingredient of Robusta coffee. Various Arabica and Robusta coffees - both green and roasted - were investigated. Free diterpenes were found in green coffees in amounts below 200 mg/kg dry matter. In comparison to the respective total diterpene content determined by the same HPLC method after saponification of the coffee oil, the proportion of free diterpenes ranged from 0.7 to 3.5 %. During the roasting process, the three uncombined diterpenes behaved similarly: free 16-O-methylcafestol, cafestol as well as kahweol were degraded with increasing roasting temperature.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 26
    Electronic Resource
    Electronic Resource
    Optimization through Factorial Planning of the Use of Ethanol : Water as a Mobile Phase for Reversed Phase HPLC (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 52-54 
    Details
    ISSN: 0935-6304
    Keywords: Ethanol ; mobile phase ; factorial planning ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 27
    Electronic Resource
    Electronic Resource
    Large Surface Area Divinylbenzene Copolymers for Size Exclusion Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 63-66 
    Details
    ISSN: 0935-6304
    Keywords: Divinylbenzene copolymers ; exclusion limit ; size exclusion chromatography ; surface area ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 28
    Electronic Resource
    Electronic Resource
    RP-HPLC and GC-MS Techniques for the Quantitative Analysis of Substituted 1,2,4-Trioxanes and their Thermolysis Products in Solution (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 67-69 
    Details
    ISSN: 0935-6304
    Keywords: RP-HPLC ; GC-MS ; trioxanes ; thermolysis products ; quantitative analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 29
    Electronic Resource
    Electronic Resource
    Development and Validation of a Reversed-Phase Liquid Chromatographic Method for Analysis of Theophylline in Human Plasma (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 131-132 
    Details
    ISSN: 0935-6304
    Keywords: RP-HPLC ; theophylline ; asthma ; apnea ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 30
    Electronic Resource
    Electronic Resource
    Semi-continuous High Speed Gas Analysis of Generated Vapors of Chemical Warfare Agents (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 153-158 
    Details
    ISSN: 0935-6304
    Keywords: Vapor analysis ; nerve agents ; sulfur mustard ; data acquisition ; automation ; valve injection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A method is presented for the continuous analysis of generated vapors of the nerve agents soman and sarin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a “standard length” column, the system can either be calibrated or used for performing high speed gas analyses. When using a flame ionization detector, the detection limit was ca. 100 ppb (ca. 0.5-1.0 mg/m3). This technique is applied in inhalation toxicokinetic studies of nerve agents and mustard gas in the guinea pig.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 31
    Electronic Resource
    Electronic Resource
    Capacity of Uncoated 0.53 mm i.d. Pre-Columns for Retaining Sample Liquid in the Presence of a Solvent Vapor Exit (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 149-152 
    Details
    ISSN: 0935-6304
    Keywords: Large volume on-column injection ; flooded zone ; capacity of 0.53 mm i. d. precolumns ; solvent trapping ; solvent vapor exit ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---0.53 mm i. d. uncoated precolumns of about 10 m in length followed by a solvent vapor exit have become a standard set-up for large volume on-column injection. It went unnoticed, however, that the introduction of a vapor exit requires two modification of previous working guidelines. First, the capacity of the precolumn to retain sample liquid is increased by a factor of 2.3-3 as a result of the around 100 times higher carrier gas flow rate. Secondly, it must be considered that this gain in retention of liquid is lost again upon closure of the exit: as the gas flow rate is reduced to a few mL/min, the layer of the residual sample liquid expands about 2.3-3 times. Hence, closure should occur late, and a section of the precolumn must be assigned for this secondary spreading.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 32
    Electronic Resource
    Electronic Resource
    Levels of Organotin Compounds in Burbot (Lota Lota) from Norwegian Lakes (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 177-180 
    Details
    ISSN: 0935-6304
    Keywords: Fresh water systems ; burbot ; organotin compounds ; speciation analysis ; GC-AED ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 33
    Electronic Resource
    Electronic Resource
    Programmable Temperature Vaporizer (PTV) Applied to the Triglyceride Analysis of Milk Fat (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 93-96 
    Details
    ISSN: 0935-6304
    Keywords: Capillary GC ; PTV and on-column injectors ; milk fat triglycerides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The PTV (Programmable Temperature Vaporizer) is a split/splitless injector which allows the sample to be introduced at a relatively low temperature, thus affording accurate and reproducible sampling. After injection the PTV is rapidly heated to transfer the vaporized components into the capillary column. This type of injector has proved to be an efficient tool for the evaluation of fatty acids, essential oils, and pesticides in food analysis. In this work the suitability of PTV for the analysis of milk fat purity by the Official EU method was evaluated. This method is based on the gas chromatographic determination of triglycerides only according to their total number of carbon atoms followed by the application of formulae deriving from multiple linear regressions. The analysis is currently carried out with a packed column or a short capillary column and an on-column injection system. Several samples of pure milk fat and mixtures of milk fat with foreign fat were analyzed with the same capillary column and by using both PTV and on-column injection systems. The results show that the gas chromatographic profile obtained by PTV is comparable with that obtained by the on-column injector, while repeatability and reproducibility data meet the requirements indicated in the Official Method. Therefore, this study demonstrates that it is possible to use the PTV instead of the on-column injector to determine the purity of milk fat with this method.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 34
    Electronic Resource
    Electronic Resource
    HPLC Control of an Alkyl Glycoside Synthesis (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 188-190 
    Details
    ISSN: 0935-6304
    Keywords: LC stationary phases ; porous graphitic carbon ; surfactant ; alkyl glycosides ; glycosides ; evaporative light scattering detection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 35
    Electronic Resource
    Electronic Resource
    Quantitative Determination of BTEX and Total Aromatic Compounds in Gasoline by Comprehensive Two-Dimensional Gas Chromatography (GC×GC) (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 195-200 
    Details
    ISSN: 0935-6304
    Keywords: Multi-dimensional gas chromatography ; comprehensive two-dimensional gas chromatography ; GC×GC ; BTEX ; aromatics ; reformulated gasoline ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Comprehensive two-dimensional gas chromatography (GC×GC) has been applied to the quantitative analysis of benzene, toluene, ethylbenzene, xylenes (BTEX), and all heavier aromatic compounds in gasoline. The two-dimensional chromatographic separation used volatility selection on the first-dimension column and polarity selection on the second-dimension column. In the resulting GC×GC chromatogram, aromatic species were resolved from other compound classes. Moreover, structurally related aromatics were grouped in a manner that facilitated identification and integration. The response of a flame ionization detector to each major aromatic group in gasoline was calibrated using internal standards. Quantitation produced results directly comparable with ASTM standard methods. The present GC×GC method can be expanded to analyze other gasoline components.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 36
    Electronic Resource
    Electronic Resource
    Membrane Extraction Combined with Thermodesorption/Gas Chromatography and Mass Selective Detection for the Analysis of Volatile Organic Compounds in Water (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 205-212 
    Details
    ISSN: 0935-6304
    Keywords: Membrane extraction ; hollow fiber membrane ; thermodesorption ; GC-MS ; volatile organic compounds ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The range of application of a commercial thermodesorption-cryofocussing unit connected to a gas chromatograph/mass selective detector was extended to water analysis by using it in conjunction with membrane extraction. A flow of nitrogen passes through a silicone hollow fiber immersed in the water sample and extracted volatile organic compounds are enriched in a sorption tube mounted on top of the extraction cell. The sorption tube is then placed in the thermodesorption unit and analyzed by GC/MS. The optimal extraction parameters of this combined method were found to be 30 min extraction at 20°C with a stirring speed of 1,250 rpm and a flow rate of 100 mL/min nitrogen using a silicone hollow fiber of 0.3 m length. Under these conditions the reproducibility of the method was 5.2-10.5% RSD. The linear dynamic range of the optimized method spans three orders of magnitude and detection limits were found to be 0.02-0.1 μg/L for cis/trans-1,2-dichloroethene, benzene, trichloroethene, chlorobenzene, bromobenzene, ethylbenzene, 1,1,2,2-tetrachloroethane, and 1,2/1,4-dichlorobenzene. The method was found to be suitable for compounds with boiling points up to 220°C as memory effects increased considerably from dichloro- to hexachlorobenzene. Highly contaminated groundwater samples were analyzed. Quantitative results corresponded well with those achieved with conventional headspace-GC/FID.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 37
    Electronic Resource
    Electronic Resource
    Determination of Phenolic Compounds in Artemisia capillaris (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 222-224 
    Details
    ISSN: 0935-6304
    Keywords: High-performance liquid chromatography ; Artemisia capillaris ; phenolic compounds separation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 38
    Electronic Resource
    Electronic Resource
    Study of the Linear Range in HPLC Analyses with UV Detection: Methodology and Experimental Application to the Influence of the Analyte UV Spectrum (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 217-221 
    Details
    ISSN: 0935-6304
    Keywords: HPLC ; UV detection ; linear range ; method validation ; Beer-Lambert law ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Determination of the linear range is one of the main concerns in validation of an HPLC analysis method. It is particularly important since single point calibration will be then used routinely. We proposed an iterative methodology to handle this problem. The idea was, at each step, to test statistically whether the following point belonged to the same regression line. The methodology was then used to evaluate quantitatively the effect on linear range of a shift in detection wavelength or of the detector bandwidth. Although experimental results were globally in accordance with spectroscopic theory, magnitudes observed were rather large. So the linear range could vary by a factor of over 2 with changes in conditions that remained within the range of current practical values. Changes in detection wavelength were limited to about fifteen nm around λmax and the detector used was considered to be representative of modern high-performance UV detectors. The question of how to take consequences in method validation into account was raised. The solution proposed recommended that the validation was undertaken in conditions as close as possible to those where the method would be conducted routinely. This means with the same instrumentation and on the product of interest for analyses.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 39
    Electronic Resource
    Electronic Resource
    Equilibrium-Sorptive Enrichment: A Novel Technique for Trace Analysis in Air (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 231-234 
    Details
    ISSN: 0935-6304
    Keywords: Trace analysis ; air samples ; BTX ; equilibrium-sorptive enrichment ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 40
    Electronic Resource
    Electronic Resource
    High Performance Liquid Chromatographic Screening and Gas Chromatography-Mass Spectrometry Confirmation of Tebuthiuron Residues in Drinking Water (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 239-241 
    Details
    ISSN: 0935-6304
    Keywords: Tebuthiuron ; GC-MS ; HPLC ; drinking water ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 41
    Electronic Resource
    Electronic Resource
    Suppressed Ion Chromatographic Determination of Chloride in Concrete (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 245-246 
    Details
    ISSN: 0935-6304
    Keywords: Chloride ; suppressed ion chromatography ; concrete ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 42
    Electronic Resource
    Electronic Resource
    Comprehensive Two-Dimensional Gas Chromatography with Mass Spectrometric Detection (GC × GC/MS) Applied to the Analysis of Petroleum (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 251-255 
    Details
    ISSN: 0935-6304
    Keywords: Multi-dimensional gas chromatography ; comprehensive two-dimensional gas chromatography ; GC × GC ; mass spectrometry ; petroleum ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Comprehensive two-dimensional gas chromatography coupled with mass spectrometric detection (GC × GC/MS) is a three-dimensional analytical method. In its application to petroleum analysis, the high peak capacity of GC × GC produced chromatographic resolution of over 750 peaks from a marine diesel fuel. The MS detector provided a full-scan mass spectrum for each resolved peak. The integration of an MS detector with GC × GC provides increased capability to identify minor components, determine members of homologous series, and characterize ordered peak patterns of related components that are visible in the GC × GC chromatogram.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 43
    Electronic Resource
    Electronic Resource
    An Unexpected Molecular Imprinting Effect for a Polyaromatic Hydrocarbon, Anthracene, Using Uniform Size Ethylene Dimethacrylate Particles (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 256-260 
    Details
    ISSN: 0935-6304
    Keywords: Molecular imprinting ; PAH ; molecular recognition ; selectivity ; redox polymerization ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A non-covalent type of molecular imprinting effect toward a polyaromatic hydrocarbon (PAH), viz. anthracene, was studied utilizing uniformly sized ethylene dimethacrylate (EDMA) polymer particles without functional host monomers. Although polymerization at 0°C initiated by a redox initiation system was expected to afford larger molecular imprinting effect due to stronger and more effective intermolecular interaction between the template and surface functional groups of the polymer, almost no imprinting effect was observed, while a much higher polymerization temperature of 70°C unexpectedly afforded a larger molecular imprinting effect for the template anthracene. In order to determine the unexpected imprinting effects observed, uniformly sized, macroporous un-imprinting EDMA polymer particles (base particles) were prepared by various polymerization techniques at different polymerization temperature as well as with different initiation systems. The careful studies proved that each kind of base polymer particle showed different molecular recognition ability, especially toward anthracene, which is depends upon the physical properties of each kind of base polymer particle. On the basis of these facts, we would propose that the potential molecular recognition ability of the un-imprinted base polymer particles is another important factor for realization of effective molecular imprinting alongside the factors reported previously.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 44
    Electronic Resource
    Electronic Resource
    Analysis of Cyclic Organic Carbonates with Chromatographic Techniques. Part 1: Ethylene Carbonate and Glycerol Carbonate (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 276-278 
    Details
    ISSN: 0935-6304
    Keywords: Cyclic carbonates ; thermal stability ; chemical stability ; gas phase chromatography ; liquid phase chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 45
    Electronic Resource
    Electronic Resource
    Improved Modification of a Laser Light-Scattering Detector for Use in Packed Capillary High Temperature Liquid Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 283-286 
    Details
    ISSN: 0935-6304
    Keywords: Evaporative light scattering detection ; capillary nebulizer ; packed capillary ; columns ; high temperature liquid chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 46
    Electronic Resource
    Electronic Resource
    Rapid Method for the Determination of Thiabendazole and Imazalil Residues in Orange by Capillary Column Gas Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 303-304 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; food analysis ; pesticide residues ; thiabendazole ; imazalil ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 47
    Electronic Resource
    Electronic Resource
    Methodology for the Determination of Cocoa Butter Replacements in Chocolate by Triacylglycerol GC Analysis (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 305-307 
    Details
    ISSN: 0935-6304
    Keywords: High temperature gas chromatography ; chocolate analysis ; triacylglycerols determination ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 48
    Electronic Resource
    Electronic Resource
    Transition Metal-Mediated Separation of Isomeric Pneumocandins by Capillary Electrochromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 309-314 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; isomers ; pneumocandins ; separation ; transition metal ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The novel separation of a 3-hydroxyproline containing a semi-synthetic macrocyclic antifungal agent from its structurally related 4-hydroxyproline isomer using capillary electrochromatography (CEC) is described. The molecular weight of the two compounds is 1093 Daltons and they differ only in the placement of a proline -OH group. The separation is achieved using capillaries packed or coated with ODS particles (C18) or with glycerol bound to silica through a carbon chain linker. The presence of a transition metal (Ni(II), Ag(I), Zn(II), or Cu(II)) as buffer additive in the phosphate buffer (pH=2.5):CH3CN (75:25, v/v) is essential to achieve a baseline separation. HPLC columns packed with similar ODS particles showed no selectivity. Capillaries packed or coated with C18 material under similar conditions showed partial selectivity compared to the glycerol capillaries. Some fundamental aspects of CEC, such as capillary temperature, applied voltage, and buffer composition were varied in order to study the mechanism of the separation. This mechanistic study included the testing of first and second row transition metal ions (individually or in combination), the use of organic solvents, the use of an ion pair reagent, and the use of β- and γ-cyclodextrin to assess the impact on the separation. The resolution was dependent on the metal ion concentration and is consistent with a mechanism of metal-oxygen complexation through the hydroxyl groups of the two isomers and glycerol.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 49
    Electronic Resource
    Electronic Resource
    Improvement of the Chemometric Variety Characterization of Wines by Improving the Detection Limit for Aroma Compounds (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 322-326 
    Details
    ISSN: 0935-6304
    Keywords: Solid phase microextraction (SPME) ; capillary gas chromatography ; detection limits ; wine aroma compounds ; classification of wines ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Headspace-SPME followed by capillary gas chromatography/mass spectrometry was used to investigate 90 German wines originating from different grape varieties, vintages, and growing areas. Aromagrams obtained in single ion monitoring (SIM) and in the full scan detection mode (SCAN) of quadrupole mass spectrometer were compared. Detection limits, reproducibility, and linearity for some aroma relevant substances were estimated over a wide concentration range. The advantages of SIM data set (lower detection limit, better reproducibility and linearity in the smaller concentration ranges) should be reflected in more reliable results in classification of wines. To verify these expectation, classification of variety by discriminant analysis was performed with cross validation using both SIM and SCAN data sets including 19 aroma compounds, respectively.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 50
    Electronic Resource
    Electronic Resource
    Improvement of the Detection Limit in Capillary Gas Chromatographic Trace Analysis of C2-C4 Hydrocarbons by Post Column Cryogenic Trapping (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 335-338 
    Details
    ISSN: 0935-6304
    Keywords: Capillary GC trace analysis of C2-C4 hydrocarbons ; signal-to-noise ratio, improvement ; post column cryogenic trapping ; thermal remobilization ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A method for the improvement of signal-to-noise ratios and hence detection limits in capillary gas chromatographic trace analysis of C2-C4 hydrocarbons was developed. It is based on the post column cryogenic trapping of the separated hydrocarbons using liquid nitrogen as coolant and its fast reinjection into the detector by rapid heating of the capillary tubing used for trapping. The improved signal-to-noise ratios were applied to decrease the sample volume and/or to lower the detection limit 10 to 27 times. The concentrations of these hydrocarbons in an urban air sample determined without and with post column cryogenic trapping were in good agreement but the precision was better when applying the cryogenic trapping mode.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 51
    Electronic Resource
    Electronic Resource
    Multidimensional Capillary GC-GC for the Analysis of Real Complex Samples. Part IV. Enantiomeric Distribution of Monoterpene Hydrocarbons and Monoterpene Alcohols of Lemon Oils (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 350-356 
    Details
    ISSN: 0935-6304
    Keywords: Multidimensional GC ; enantioselective gas chromatography ; lemon oil ; monoterpene hydrocarbons ; monoterpene alcohols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---This paper describes a fully automated, multidimensional, double-oven GC-GC system, developed in our laboratory. The system is based on the use of mechanical valves which allow the multitransfer of different fractions during the same GC analysis and the use of the two GC independently when the multitransfer options is not used. Pneumatic and electronic circuits permit maintenance of constant retention times in the pre-column, even for the components eluted after numerous transfers. The system has been used for the determination of the enantiomeric distribution of β-pinene, sabinene, limonene, linalol, terpinen-4-ol, and α-terpineol in lemon oils. The results obtained allowed the characterization of cold-pressed lemon oils.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 52
    Electronic Resource
    Electronic Resource
    Effect of Injector Conditions on the Reproducibility of Gas Chromatographic-Electron Capture Detection of Sterol Derivatives and Synthetic Pyrethroids (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 362-366 
    Details
    ISSN: 0935-6304
    Keywords: Pentafluorophenyldimethylsilyl (flophemesyl) chloride ; split and splitless injection ; derivatised sterol analysis ; synthetic pyrethroids ; injector liner activity ; gas chromatographic electron capture detection ; multidimensional gas chromatography ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 53
    Electronic Resource
    Electronic Resource
    Sweeping with an Enhanced Electric Field of Neutral Analyte Zones in Electrokinetic Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 367-372 
    Details
    ISSN: 0935-6304
    Keywords: Sweeping ; sample stacking ; micellar electrokinetic chromatography (MEKC) ; retention factor (k) ; sample matrix ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concept of sweeping has been used in electrokinetic chromatography to explain the concentrating mechanism in micellar electrokinetic chromatography when the sample matrix is a high resistivity non-micellar aqueous solution. Theoretical and experimental studies were undertaken. It was found that the total focusing effect is brought about by the cumulative effect of sweeping and sample stacking. For better analytical results, compounds showing low to moderate retention factors (k) and compounds showing high values of k must be dissolved in low and high conductivity matrices, respectively.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 54
    Electronic Resource
    Electronic Resource
    Simultaneous Determination of Inorganic Anions and Organic Acids in Environmental Samples by Capillary Zone Electrophoresis with Indirect UV Detection (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 379-385 
    Details
    ISSN: 0935-6304
    Keywords: CZE ; indirect UV detection ; anions and organic acids ; environmental samples ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Capillary zone electrophoresis (CZE) with indirect UV detection was developed for the simultaneous determination of inorganic anions and organic acids in environmental samples. Various aromatic acids (benzoic, phthalic, trimellitic, and pyromellitic acids) were evaluated as background electrolytes (BGEs) to give high resolution and detection sensitivity. Co-electroosmotic conditions such as the concentration of BGE, electrolyte pH, and EOF modifier were systematically investigated. Three inorganic anions and ten organic acids were determined simultaneously in 10 min using an electrolyte containing 10 mM phthalic acid, 0.5 mM myristyltrimethylammonium bromide (MTAB), and 5% methanol (MeOH) (v/v) at pH 5.60. Linear plots for the test solutes were obtained in the concentration range 0.01-1.0 mM with detection limits in the range 5-30 μM. The proposed method was successfully demonstrated for the determination of inorganic anions and organic acids in natural water, soil, and plant extracts after direct sample injection.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 55
    Electronic Resource
    Electronic Resource
    Pulsed Splitless Injection and the Extent of Matrix Effects in the Analysis of Pesticides (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 395-402 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; pulsed splitless injection ; pesticide residues ; matrix effects ; retention gap ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The applicability of pulsed splitless injection to the gas chromatographic analysis of pesticide residues in fruit and vegetables has been evaluated. 22 pesticides belonging to different chemical classes, including those known to be liable to matrix induced response enhancement, were selected for the study. The parameters of pressure pulse have been tested for optimum performance of injection. Application of the pressure pulse was found to decrease matrix effects during analyses of real samples. Further decline of matrix effects was obtained using higher sample injection volumes. The installation of a deactivated retention gap was necessary to obtain good peak shapes with injection volumes exceeding 1 μL of sample. Up to 4 μL was then injected without peak distortion and consequent loss of resolution. Using 4 μL pulsed splitless injection, matrix effects were almost completely eliminated even at very low concentration levels of analytes. The highest matrix effects observed for tested compounds at the lowest concentration level tested were in the range of 110-122%.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 56
    Electronic Resource
    Electronic Resource
    Theory of Fast Capillary Gas Chromatography - Part 3: Column Performance vs. Gas Flow Rate (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 403-413 
    Details
    ISSN: 0935-6304
    Keywords: Constant length optimization ; constant efficiency optimization ; efficiency-optimized flow rate ; fast GC ; film inefficiency factor ; high pressure drop ; speed-optimized flow rate ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: At the high pressure drop required for the fast analysis of complex mixtures, the equations for the column plate height, H, and plate duration, Q, as functions of the carrier gas velocity, u, differ substantially from the equations for the same quantities expressed via the carrier gas flow rate, F. While u as an independent pneumatic variable is more convenient for the theoretical studies, F is a more convenient as a control parameter in practical applications. Equations for H vs. u and for Q vs. u from Parts 1 and 2 are transformed here into expressions for H vs. F and Q vs. F. An efficiency-optimized flow rate (EOF) and a speed-optimized flow rate (SOF) are found. Expressions for these two quantities are considerably simpler than their velocity-based counterparts. In particular, SOF does not depend on column length, film thickness, and pressure drop.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 57
    Electronic Resource
    Electronic Resource
    Temperature-Dependence of Supported-Liquid-Membrane Extraction (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 417-420 
    Details
    ISSN: 0935-6304
    Keywords: Sample preparation ; nitrophenols ; PCP ; 2,4-D ; liquid chromatography ; supported-liquid-membrane extraction ; environmental monitoring ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 58
    Electronic Resource
    Electronic Resource
    Total p-Chlorophenol Determination in Urine Samples of Subjects Exposed to Chlorobenzene, Using SPME and GC-MS (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 427-428 
    Details
    ISSN: 0935-6304
    Keywords: p-Chlorophenol ; urine ; SPME ; GC/MS ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 59
    Electronic Resource
    Electronic Resource
    Determination of Trichothecene Toxin (T2 Mycotoxin) in Aqueous Sample with Solid Phase Microextraction Technique Followed by Gas Chromatography with Flame Ionization Detection (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 424-426 
    Details
    ISSN: 0935-6304
    Keywords: Mycotoxin ; T2 ; solid phase microextraction ; GC/FID ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 60
    Electronic Resource
    Electronic Resource
    Separation of Chlorophylls and Their Degradation Products using Packed Column Supercritical Fluid Chromatography (SFC) (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 339-342 
    Details
    ISSN: 0935-6304
    Keywords: Chlorophyll ; SFC ; supercritical fluid chromatography ; vegetables ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Complex mixtures of chlorophyll degradation products may arise during processing and storage of vegetable oil and green plant materials like broccoli and spinach. Determination of these compounds is important in the area of food chemistry. Therefore a method using packed column supercritical fluid chromatography (SFC) has been developed. The method comprises chromatography using a simple gradient of methanol in carbon dioxide at constant column back pressure of 30 MPa and a column temperature of 40°C. Effects of pressure and mobile phase composition showed the importance of applying a modifier gradient for optimal separation of the chlorophyll products. The method permits separation of 15 chlorophyll derivatives including chlorophyll a and b, pheophytins, and pyropheophytins on a C18 column in about 20 minutes. Identifications of the individual peaks were based on reference compounds, the retention order of the compounds, and their absorption spectra.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 61
    Electronic Resource
    Electronic Resource
    HRGC/FID and HRGC/MSD Analysis of the Secondary Metabolites Obtained by Different Extraction Methods from Lepechinia schiedeana, and in Vitro Evaluation of Its Antioxidant Activity (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 343-349 
    Details
    ISSN: 0935-6304
    Keywords: Capillary gas chromatography ; gas chromatography-mass spectrometry ; essential oil analysis ; Lepechinia schiedeana ; antioxidant activity ; lipid peroxidation ; Ledol; Ledol HMQC ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Steam distillation (SD), simultaneous distillation-solvent extraction (SDE), microwave-assisted solvent extraction (MWE), and supercritical (CO2) extraction (SFE) were used to isolate secondary metabolites from Lepechinia schiedeana. The various extracts were analyzed by capillary gas-chromatography, on poly (dimethylsiloxane) (DB-1) and poly(ethyleneglycol) (INNOWAX), 60 m columns, using FID or MSD (EI, 70 eV). Kováts indexes, mass spectra, or standard compounds were employed for compound identification. 43, 61, 67, and 79 compounds at concentrations above 0.01% were detected in the SD, SDE, MWE, and SFE extracts, respectively. Ledol, C15H26O, was the major constituent (20.04-36.87%) in all extracts. Oxygenated sesquiterpenes (24.36-43.14%), C10H16, monoterpenes (27.70-39.87%), and C15H24, sesquiterpenes (10.04-22.22%) were the main groups of compounds present in SD, SDE, MWE, and SFE extracts. Heavy hydrocarbons (Cn 〉 15), diterpenoids, and phytosterols were found only in MWE and SFE extracts. The antioxidant activity of Lepechinia schiedeana was measured by the HRGC quantification of the volatile carbonyl compounds, final products of lipoxidation, released in a model lipid system (sunflower oil) by the effect of the Fenton reagent. The concentration of volatile carbonyl compounds decreased by 65% when lipid oxidation was induced in the presence of macerated Lepechinia plant. The protection of polyunsaturated acids in sunflower oil was also studied by measuring their concentrations after heating of the oil (180°C, 2 h) with and without macerated Lepechinia plant.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 62
    Electronic Resource
    Electronic Resource
    Use of Isopropanol as a Modifier in a Hexane-Acetonitrile Based Mobile Phase for the Silver Ion HPLC Separation of Positional Isomers of Triacylglycerols Containing Long Chain Polyunsaturated Fatty Acids (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 357-361 
    Details
    ISSN: 0935-6304
    Keywords: Silver ion HPLC ; long chain polyunsaturated fatty acid ; isopropanol ; separation of positional isomers ; degree of unsaturation ; normal phase retention effect ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A high resolution approach to silver ion HPLC was studied for the separation of positional isomers of triacylglycerols (TAGs) containing long chain polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA) in enzymatically synthesized structured TAGs. Isopropanol was used as a novel modifier in a hexane-acetonitrile based mobile phase for silver ion HPLC. Peak identification was based on HPLC-mass spectroscopy and selectivities of lipases. Positional isomers of TAGs containing one molecule of EPA, DHA, or DPA with saturated fatty acids (FAs) such as caprylic acid and palmitic acid were separated within 13 min using a gradient of hexane-isopropanol-acetonitrile as mobile phase. TAGs containing two or more EPA, DHA, or DPA were also separated from each other within 25 min, but their positional isomers were unresolved. The retention characteristics of the TAG were found to be related to the number of carbon atoms in the FAs present in addition to the number of double bonds and their isomeric configuration. One isomer with an unsaturated FA in the sn-2 position eluted faster than the other with the unsaturated FA in the sn-1 or 3 position. Species with longer chain FAs attached to TAGs with the same degree of unsaturation eluted faster than those that have shorter chain FAs. For example, docosapentaenoylhexadecanoyloctanoin (DPA/C16/C8) was eluted faster than dioctanoyldocosapentaenoin (DPA/C8/C8).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 63
    Electronic Resource
    Electronic Resource
    A Computer Method for Predicting the Electrophoretic Mobility of Peptides (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 373-378 
    Details
    ISSN: 0935-6304
    Keywords: Electrophoresis ; electrophoretic mobilities ; CZE ; MEKC ; peptides ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A computer model is presented for the prediction of the electrophoretic mobilities of peptides from physical constants derived from their amino acid sequences. The model assumes that the electrophoretic mobility can be represented by a product of four functions according to the relation:  lcomp= l(L)w(W)q(Q)c(CC), where L (a length parameter) is represented by the number of amino acid residues of the peptide, W (a width parameter) is represented by the average residue mass, Q = the charge of the peptide, and CC = the position of the center of charge relative to the center of mass. The model was used to calculate the electrophoretic mobilities of peptides in a 50 mM phosphate buffer at pH 2.5. Sixty-four test peptides ranging in size from 2 to 39 amino acid residues were used for this study. The calculated mobilities show excellent correlation with experimental measurements with a correlation coefficient greater than 0.98.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 64
    Electronic Resource
    Electronic Resource
    Simultaneous Measurement of Hydrocarbons and Sulfur Compounds using Flame Ionization and Sulfur Chemiluminescence Detection for Sulfur Simulated Distillation (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 386-390 
    Details
    ISSN: 0935-6304
    Keywords: Sulfur chemiluminescence detection ; sulfur simulated distillation ; boiling point distribution ; simultaneous FID/SCD analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A gas chromatographic system for the simultaneous acquisition of hydrocarbon and sulfur chromatograms was developed. Detection of sulfur compounds is achieved using a sulfur chemiluminescence detector (SCD) mounted in series with a flame ionization detector (FID). A constant fraction of the effluent of the FID is transferred to the SCD by means of a fixed restrictor. Unlike previous versions of this approach, the FID is not used to generate the chemiluminescent sulfur species. Rather, the FID is operated under optimum conditions for hydrocarbon analysis and a furnace is used to generate the chemiluminescent sulfur species. The system permits dual acquisition of the hydrocarbon and sulfur signals in a single analysis with a single column, since the detectors are operated in a serial fashion. The application of sulfur simulated distillation using this approach was examined, since this requires simultaneous universal and sulfur selective detection. Precision of absolute response of both the FID and SCD was typically less than 2% RSD for a standard reference material.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 65
    Electronic Resource
    Electronic Resource
    A Novel Interface for Optimized Coupling of Gas Chromatography and Supersonic Jet Spectroscopy (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 391-394 
    Details
    ISSN: 0935-6304
    Keywords: REMPI-TOFMS ; laser mass spectrometry ; supersonic jet ; GC-MS ; interface ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The laser-based methods Laser Induced Fluorescence (LIF) and Resonance-Enhanced Multi-Photon Ionization (REMPI) can be used as highly selective detection modes for gas chromatography (GC). One major prerequisite for successful application of these detection methods is the availability of appropriate and reliable interfaces between the GC effluent and the molecular beam inlet. When a pulsed supersonic molecular beam (jet) source is used, the analyte molecules are efficiently cooled, allowing maximum selectivity of the laser spectroscopic detection methods. However, several technical problems have to be solved for practical realization of a GC-supersonic jet valve hyphenation. The pulsed jet interface should not interfere with the GC properties and the supersonic molecular beam properties. Further a good working cycle for the conversion from the continuously flowing GC current to the pulsed jet gas flow should be attained. This paper presents a novel setup of a GC-pulsed jet interface. The construction allows temporal and spatial compression of the analyte molecules in jet gas pulse and thus an increase of the detection sensitivity. Moreover, the GC effluent comes into contact only with glass surfaces and not with valve parts like plungers and seals. This reduces memory effects and sample decomposition. The valve setup is tested with a REMPI-TOFMS instrument.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 66
    Electronic Resource
    Electronic Resource
    Selective Determination of Se4+ and Se6+ Using SPME and GC/MS (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 414-416 
    Details
    ISSN: 0935-6304
    Keywords: Selenium ; water ; SPME ; GC/MS ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A method for the selective determination of Se4+ and Se6+ using solid phase microextraction (SPME) and GC/MS analysis is presented. Se4+ is selectively derivatized by reaction with 4,5-dichloro-1,2-phenylenediamine to form the corresponding piazselenolo complex, extracted by the SPME fiber, and determined by GC/MS. The RSD at a 5 μg/L concentration was 9.88% and the theoretical detection limit 6 ng/L. The method was employed to test real matrices; tap and river water were analyzed before and after spiking giving a recovery rate of 102% in river water and 97% in tap water.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 67
    Electronic Resource
    Electronic Resource
    γ-Dithiolactones - Analytical and Sensory Characteristics (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 421-423 
    Details
    ISSN: 0935-6304
    Keywords: Enantioselective gas chromatography ; 2,3-di-O-methyl-6-O-tert-butyldimethylsilyl-β-cyclodextrin ; 2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl-β-cyclodextrin ; γ-dithiolactones ; olfactometry ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 68
    Electronic Resource
    Electronic Resource
    Determination of Biological Oxidative Stress Using High Performance Liquid Chromatography with Electrochemical Detection (HPLC-ECD) (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 429-437 
    Details
    ISSN: 0935-6304
    Keywords: HPLC ; nitrotyrosine ; nitrotocopherol ; analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---For three decades, high performance liquid chromatography has proven itself to be a powerful, flexible, and inexpensive tool for basic and clinical research. Recent advances in our understanding of disease have prompted a demand for more sensitive and selective methods of routine bioanalysis, particularly with respect to the determination of oxidative metabolites and biomarkers of oxidative stress. Multidimensional detectors utilizing coulometric arrays offer a solution to these research needs. The challenge to the bioanalyst is now to creatively apply HPLC-ECD technology to promising research and clinical enterprises.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 69
    Electronic Resource
    Electronic Resource
    Optimization and Parameter Study for Chiral Separation by Capillary Electrophoresis (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 449-453 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrophoresis ; experimental design ; cyclodextrin ; chiral separation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Orthogonal design and uniform design were used for the optimization of separation of enantiomers using 2,6-di-O-methyl-β-cyclodextrin (DM-β-CD) as a chiral selector by capillary zone electrophoresis. The concentration of DM-β-CD, buffer pH, running voltage, and capillary temperature were selected as variable parameters, their different effects on peak resolution were studied by the design methods. It was concluded that orthogonal design offers a rapid and efficient means for testing the importance of individual parameters and for determining the optimum operating conditions. However, for a large number of both factors and levels, uniform design is more efficient. The effect of addition of methanol and citric acid buffer on the separation of enantiomers was also examined.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 70
    Electronic Resource
    Electronic Resource
    Functionalized Polymeric Sorbents for Solid-Phase Extraction of Polar Pollutants (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 547-552 
    Details
    ISSN: 0935-6304
    Keywords: Water analysis ; polar pollutants ; solid-phase extraction ; chemically-modified polymeric resins ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---This study assesses how the physical characteristics of styrene-divinylbenzene (PS-DVB) resins affect the extent to which they are modified when they are functionalized, and how they affect recoveries in on-line solid-phase extraction (SPE) of some polar phenolic compounds, pesticides, and metabolites from water samples which were analyzed by liquid chromatography and UV detection. For this purpose, three commercial PS-DVB resins with different physical characteristics (Amberchrom GC-161m and two different PLRP-S resins) were chemically modified by placing a hydrophilic group, an o-carboxybenzoyl moiety, on their surface; although the physical characteristics are different, the extent of modification did not vary significantly. The results from the SPE process with each sorbent were related to their physical and chemical properties. The polymers with higher surface area provided better recoveries. Moreover, the recoveries for these analytes were better with the chemically-modified polymers due to the higher polarity of these sorbents. The best recovery values were with the sorbent obtained from the chemical modification of Amberchrom GC-161m, the commercial sorbent with higher surface area. For instance, in the analysis of 50 mL of a sample of 2 μg L-1, the recovery of phenol was 40% with Amberchrom GC-161m and 65% with the chemically-modified Amberchrom GC-161m.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 71
    Electronic Resource
    Electronic Resource
    Determination of Vapor Liquid Equilibrium from the Kovats Retention Index on Dimethylsilicone using the Wilson Mixing Model (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 565-588 
    Details
    ISSN: 0935-6304
    Keywords: Gas chromatography ; Kovats retention index ; vapor pressure ; boiling point ; Wilson activity coefficient ; binary phase diagrams ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Non-ideal mixing in a dimethylsilicone stationary phase is modeled according to the Wilson activity coefficient. Pure liquid vapor pressures of alkylated compound series are calculated from capillary GLC retention with the functional group heat of solution in a polymer solvent. The new method uses the Kovats index, molar mass, and functional group to determine the bubble line of a compound. Boiling points at reduced and normal pressure are compared to literature values of 194 gasoline components. An unlike molecular pair interaction parameter is derived, using only bubble line data of the pure liquids. Binary phase diagrams are constructed and compared to vapor liquid equilibrium data.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 72
    Electronic Resource
    Electronic Resource
    A Strategy for the Simplification and Solution of Complex Chromatographic Analysis Problems Utilizing Two-Dimensional Mapping of Retention Indexes Followed by Computer Modeling of Heart Cuts from Serially Coupled Columns Containing Different Stationary Phases (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 589-593 
    Details
    ISSN: 0935-6304
    Keywords: Computer modeling of GC ; computer simulation of GC ; computer-assisted GC analysis ; GC multicolumn analysis ; heart cutting GC analysis ; computer-assisted column design ; computer-assisted selectivity tuning ; retention index mapping ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The analysis of four components in a mixture containing many possible interferents is simplified by heart-cutting serially connected columns containing stationary phases of widely different polarities. The design of the proper lengths of the two columns and timing the heart-cuts is accomplished with the aid of a computer simulation of the problem. The computer program calculates the proper lengths of column to produce the shortest analysis time and also outputs the predicted chromatograms from both columns. The chromatogram from the first column is used to construct the timing gates for the heart-cuts and the chromatogram from the second or analytical column is used to set integration gates for the selected compounds of interest.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 73
    Electronic Resource
    Electronic Resource
    Temperature-Programmed Packed Capillary Liquid Chromatography Separation with Large Volume On-Column Focusing of Retinyl Esters (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 490-494 
    Details
    ISSN: 0935-6304
    Keywords: Large volume injection ; packed capillary LC ; temperature programming ; retinyl esters ; vitamin A ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A non-aqueous isocratic reversed-phase packed capillary high performance liquid chromatography method for the determination of retinyl esters, utilizing temperature programming and on-column focusing large volume injection, has been developed. The stationary phase material was C30, and the mobile phase consisted of acetonitrile-dichloromethane (70 : 30, v/v). A three-step temperature program, starting at 10°C for 10 min, then 1°/min to 30°C, and finally 2.5°/min to 70°C, was found most appropriate. Compared to an isothermal separation at 25°C, this temperature program provided improved peak resolution, enhanced peak shapes of the last eluting compounds, and a reduction of the overall elution time. A mass limit of detection of 27 pg was found with respect to retinyl palmitate, using UV detection with an “U” shaped flow cell at 327 nm. This corresponds to a concentration limit of detection of 2.7 pg/μL, when utilizing an injection volume of 10 μL. The concentration of retinyl palmitate in arctic seal liver samples was estimated to be 62.6 μg/g liver.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 74
    Electronic Resource
    Electronic Resource
    Theory of Fast Capillary Gas Chromatography Part 4: Column Performance vs.Liquid Film Thickness (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 501-508 
    Details
    ISSN: 0935-6304
    Keywords: Fast GC ; film inefficiency factor ; high pressure drop ; thick film columns ; thin film columns ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The negative effect of the liquid stationary phase film thickness on the column efficiency is strongest for peaks with retention factors, k, in the vicinity of k = 0.3-0.4 and rapidly diminishes with the departure of k from that region. Additionally, at the high pressure drop required for fast analysis of complex mixtures, the negative effect of the same film thickness diminishes with the increase in column length, regardless of the k values. In practice, it is recommended to ignore the film thickness and optimize the columns as thin film ones regardless of their actual film thickness. Accounting for the film thickness results only in a modest improvement in the resolution for a few affected peaks - those with k = 0.3-0.4. However, this improvement comes at the cost of a substantial increase in analysis time, and should be used only as the action of the last resort.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 75
    Electronic Resource
    Electronic Resource
    Isolation and Characterization of Wax Esters in Fennel and Caraway Seed Oils by SPE-GC (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 514-520 
    Details
    ISSN: 0935-6304
    Keywords: Solid-phase extraction ; high temperature - gas chromatography ; gas chromatography - mass spectrometry ; wax esters fennel seed oil ; caraway seed oil ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A rapid method for the isolation and quantitative determination of wax esters in vegetable oils was developed. For the first time wax esters in oils were separated from the triglyceride matrix by means of solid-phase extraction, which allows rapid sample preparation in parallel and therefore a high sample throughput. The thus obtained wax ester fractions of fennel and caraway seed oils were analyzed by high temperature gas chromatography. GC-MS analyses were carried out using electron impact ionization in order to characterize the wax ester fraction. With respect to the results of the GC-MS analyses different isomers of saturated wax esters with the same carbon number were observed. Additional monounsaturated wax esters with an unsaturated fatty acid moiety were identified.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 76
    Electronic Resource
    Electronic Resource
    Comparative Methodology for Isolation of Flavonoid Glycosides from Clusia criuva Cambess (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 527-530 
    Details
    ISSN: 0935-6304
    Keywords: Clusia criuva Cambess ; counter-current chromatography ; flavonoids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The family Guttiferae belongs to the superorder Theiflorae, order Theales and according to Dahlgren's system of classification, it is equivalent to Hypericaceae (=Clusiaceae) [1]. This family consists of 49 genera encompassing over 1000 species of wide distribution in the tropics as shrubs and trees [2]. Plants of the genus Clusia have been used in folk medicine for the treatment of different kind of illness such as: febrifuge, anti rheumatic, purgative, for stomach problems and, in Brazil, they are very commonly used to heal wounds [3]. The key of any study of material from natural sources is the availability of suitable separation methods for the isolation of pure products [4-6]. Tentatives for separations using chomatography on solid support phases were not very efficients in the fractionation of Clusia criuva Cambess methanolic/ethyl acetate extracts. However, the use of counter-current chromatography, an all liquid technique, showed advantages in comparison with the more traditional liquid-solid separation methods and even with HPLC. In this sense it was possible to isolate flavonoid glycosides from ethyl acetate extract of Clusia criuva, in a very short operation time.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 77
    Electronic Resource
    Electronic Resource
    Fast Solvating Gas Chromatography of Environmentally Important Compounds Using Polymer-Encapsulated Silica Particles (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 541-546 
    Details
    ISSN: 0935-6304
    Keywords: Solvating gas chromatography ; gas chromatography ; fast separation ; pesticides ; herbicides ; aldehydes ; packed capillary columns ; polymer-encapsulated silica ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Rapid separations of selected environmentally important polar compounds using polymer-encapsulated silica stationary phases and a carbon dioxide mobile phase under solvating gas chromatography (SGC) conditions are reported. Ten underivatized short chain aldehydes and ten nitrogen-containing herbicides were separated within 1 min and 5 min, respectively, using a 30 cm×250 μm i. d. column packed with diol-bonded, polyethylenimine (PEI)-coated, and hexamethyldisilazane (HMDS)-end-capped silica particles (5 μm, 120 Å). Seven organophosphorus pesticides were resolved in less than 5 min using a 30 cm×250 μm i. d. column packed with polymethylhydrosiloxane-deactivated and SE-54 encapsulated silica particles. Separation numbers per unit time increased with pressure and temperature ramps. Both rapid pressure and temperature programming can be used to increase the speed of SGC. The effects of pressure and temperature on apparent retention factors of solutes with various polarities were investigated using diol-PEI-HMDS silica particles in SGC.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 78
    Electronic Resource
    Electronic Resource
    Evaluation of Dead Time Calculation in Reversed-Phase Liquid Chromatography Using a Multiparametric Mathematical Method (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 559-564 
    Details
    ISSN: 0935-6304
    Keywords: Liquid chromatography ; dead time ; multiparametric least-squares adjustment ; homologous series ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In reversed phase liquid chromatography (RP-HPLC), the validity of a multiparametric non-linear least-squares regression iterative method for the determination of the column dead time tM and the regression parameter (slope b), based on the use of alkan-2-ones, alkyl aryl ketones, and 1-nitroalkanes has been evaluated. The determination of tM and b has been extensively studied for two mobile phase systems acetonitrile-water and methanol-water on seven octadecyl-C18 and one octyl C8 analytical columns. The calculated tM and b values were compared with those obtained by Guardino's and Grobler's methods. The influence exerted thereon by the nature of the homologous series, the mobile phase composition, and the packing materials were investigated.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 79
    Electronic Resource
    Electronic Resource
    Supercritical Fluid Extraction (SFE) Optimization by Full-Factorial Design for the Determination of Irganox 1076, Irgafos 168, and Chimassorb 81 in Virgin and Recycled Polyolefins (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 553-558 
    Details
    ISSN: 0935-6304
    Keywords: SFE ; experimental design ; additives ; recycling ; polyolefins ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The performance and feasibility of supercritical fluid extraction (SFE) applied to the extraction of some antioxidants (Irganox 1076, Irgafos 168) and one UV-stabilizer (Chimassorb 81) from both virgin and recycled low density polyethylene (LDPE), and virgin high density polyethylene (HDPE) are studied. Due to the high number of variables a full-factorial design has been applied to minimize the number of experiments required to reach the optimum extraction conditions. Further analysis has been carried out off-line by reversed-phase HPLC. Modification of the physical properties of the polymeric matrix and increased number of recycling cycles as well as the influence of physical properties on the efficiency of SFE are also discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 80
    Electronic Resource
    Electronic Resource
    Capillary Electrophoresis as an Efficient Tool in the Determination of Low Association Constants between Polyhydroxy Compound and Samarium Cation (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 595-598 
    Details
    ISSN: 0935-6304
    Keywords: Xylitol ; samarium ; weak association ; equilibrium constant ; capillary electrophoresis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 81
    Electronic Resource
    Electronic Resource
    Effects of Blending Bare-Silica and Reversed-Phase on Retention of Neutral Compounds in Capillary Electrochromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 599-603 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; retention ; mixed stationary phases ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Most commercially available instruments for capillary electrochromatography (CEC) have a fixed configuration and lack the flexibility to use shorter columns. Applying a blended stationary phase (a phase consisting of a given ratio of bare silica and reversed phase material) can simulate columns of different length in CEC. The goal of this work was to examine the effect of the degree of blending of reversed-phase columns (with bare silica) on the speed of the separation of neutral compounds in CEC. Optimum column packing mixture was determined from the variation of the solute retention factors as a function of the ratios of blending of reversed-phase and bare silica. By adjusting the column composition, solute retention factors and the analysis run time were halved when compared to a pure reversed-phase column of the same length. Stationary phase blending can be considered as an additional parameter to mobile phase variation, column temperature and applied electric field for the optimization of selectivity and analysis time. By adjusting the stationary phase composition, mobile phase composition, column temperature and applied electric field, the analysis run time of neutral components was decreased more than 75% when compared to a separation obtained on neat reversed-phase column of the same dimensions. The linear dependence of the retention factors as a function of the blend ratio (reversed phase/bare silica) offers a framework for designing a “blended” packed capillary column for CEC separations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 82
    Electronic Resource
    Electronic Resource
    Comparison of Retention Indices of Some Explosives and Related Compounds Calculated by Different Mathematical Methods in Reversed-Phase Liquid Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 613-618 
    Details
    ISSN: 0935-6304
    Keywords: Liquid chromatography ; retention index ; multiparametric least-squares adjustment ; homologous series ; nitramines ; nitroaromatics ; aminoaromatics and nitrophenols ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---In reversed phase liquid chromatography, the retention indices of some neutral and acidic explosives and related compounds (nitramines, nitroaromatics, aminoaromatics, and nitrophenols) based on the alkan-2-one, alkyl aryl ketone, and 1-nitroalkane retention index standards have been determined by the application of a new mathematical adaptation method, viz. a multiparametric least-squares regression iterative method. This method was applied to two types of columns. The first group includes six octadecyl-C18 columns with different packing materials and obtained from different manufacturers, while the second group comprises one octyl-C8 column. The retention indices have been extensively studied using either methanol-water or methanol-phosphate buffer mobile phase systems. The calculated multiparametric retention indices values were compared with those obtained by Guardino's, Grobler's, and Kovàts' methods. The influences of the concentration of the organic modifier in the mobile phase, aqueous mobile phase pH, and the column packing material on the retention indices of the explosives were also investigated. Good agreement was observed between the retention indices calculated by the use of the four mathematical methods for both neutral and acidic explosives.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 83
    Electronic Resource
    Electronic Resource
    Extraction and Clean-Up Method for the Determination of Twenty Organochlorine Pesticide Residues in Tomatoes by GLC-ECD (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 619-622 
    Details
    ISSN: 0935-6304
    Keywords: Organochlorine compounds ; pesticides ; food analysis ; tomatoes ; GLC-ECD ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A method is described for the simultaneous extraction and determination of twenty organochlorine pesticides residues [hexachlorocyclohexane (HCH) isomers (α, β, γ, δ), aldrin, dieldrin, endrin, heptachlor and its epoxide (HE), hexachlorobenzene (HCB), α-endosulfan, o,p′-DDD, p,p′-DDD, o,p′-DDE, p,p′-DDE, o,p′-DDT, p,p′-DDT, dicofol, methoxychlor, and mirex] that were spiked in tomatoes. Samples were extracted with ethyl acetate, and the extract was subjected to a rapid clean-up using a Florisil column. The residues were determined by GLC-ECD using two columns of different polarity. The calibration graph correlation coefficient ranged from 0.9903 to 0.9990. The recoveries ranged from 95 to 99% with relative standard deviation ranging from 0.5 to 14.7% in the concentration range 0.005 to 0.2 μg/g. The limits of detection ranged from 0.004 to 0.05 μg/g and the limits of quantification ranged from 0.005 to 0.174 μg/g.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 84
    Electronic Resource
    Electronic Resource
    Total p-Nitrophenol Determination in Urine Samples of Subjects Exposed to Parathion and Methyl-Parathion by SPME and GC/MS (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 628-630 
    Details
    ISSN: 0935-6304
    Keywords: p-Nitrophenol ; urine ; SPME ; GC/MS ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 85
    Electronic Resource
    Electronic Resource
    A Rapid Method for Fingerprinting the Organic Fraction in Archeological Samples Using a PTV as a Thermodesorber (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 635-638 
    Details
    ISSN: 0935-6304
    Keywords: High resolution gas chromatography ; thermal desorption ; archeological cosmetic powders ; PTV injector ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---No abstract
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 86
    Electronic Resource
    Electronic Resource
    Properties and Applications of Mixed Packing Capillary Electrochromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 666-670 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; mixed packing technique ; electroosmotic flow ; retention mechanism ; fast analysis ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mixed packing capillary electrochromatography (MP CEC) with the stationary phase comprising a physical mixture of strong cation exchange (SCX) phase and octadecysilyl (ODS) phase was developed. With the existence of a sulfonic acid group on the surface of SCX, not only could the electroosmotic flow (EOF) remain high at low pH, but also the hydrophilicity of the stationary phase was increased greatly, leading to broad adaptable ranges of both pH and organic modifier concentration in the mobile phase. At the same time, with the coexistence of C18 on the surface of ODS, both the retention and the resolution of samples were improved. Accordingly, MP CEC combined the advantages of both SCX and ODS columns. Effects of operation parameters on EOF and the capacity factors of solutes as well as the retention mechanism of such a column were studied systematically. In addition, MP CEC columns were used in the analysis of strong polar solutes as well as for the high speed separation of acidic, basic, and neutral compounds in a single run.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 87
    Electronic Resource
    Electronic Resource
    Cyclocholates as Chiral Selectors for Capillary Gas Chromatography - Effect of Temperature Conditioning on the Chromatographic Behavior of the Stationary Phase (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 671-678 
    Details
    ISSN: 0935-6304
    Keywords: Enantioselective capillary gas chromatography ; chiral stationary phase ; chiral recognition mechanism ; cholic acid ; cyclocholates ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The suitability of cyclocholates as chiral selectors in gas chromatography has been evaluated. We present the synthesis and characterization of two cyclocholates, viz. 3α,7α-diacetoxycyclo[3]cholate and 3α,7α-diacetoxycylo[4]cholate. Mixtures of these new selectors with polysiloxanes were tested as chiral stationary phases in capillary gas chromatography. Several enantiomer separations of common racemates were achieved with the 3α,7α-diacetoxycyclo[3]cholate at 10% in OV-1701 (w/w). It was shown that column efficiency was strongly dependent on temperature and that enantioselectivity was very sensitive to column conditioning. This chromatographic behavior suggested that cyclocholates were only dispersed in polysiloxane. Thus, it was assumed that chiral discrimination occurred via enantioselective adsorption interactions of enantiomers at the surface of the solid chiral selector dispersed in the polysiloxane matrix OV-1701.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 88
    Electronic Resource
    Electronic Resource
    Comparative Study of Packed and Capillary Column Chromatography for the Characterization of Vacuum Gas Oils (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 683-686 
    Details
    ISSN: 0935-6304
    Keywords: Vacuum gas oils ; packed column chromatography ; n-paraffins ; carbon number distribution ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Gas chromatographic methods are of widespread use in the petroleum industry for assessing petroleum and derivatives quality. The feedstocks for catcracking processes are very sensitive to the n-paraffin contents, which can be accurately determined using capillary column chromatography. Nevertheless, packed column chromatography does have potential advantages, viz. sometimes shorter analysis times, lower costs, higher column capacity, for vacuum gas oil analysis. This paper presents a method for such a determination using a Dexsil-300 packed column. The results obtained (n-alkane contents, carbon number distribution) agree fairly well with those obtained on a 30 m × 0.25 mm DB-1 fused silica capillary column.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 89
    Electronic Resource
    Electronic Resource
    Automated On-Line GPC-GC-FPD Involving Co-Solvent Trapping and the On-Column Interface for the Determination of Organophosphorus Pesticides in Olive Oils (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 17-23 
    Details
    ISSN: 0935-6304
    Keywords: Coupled GPC-GC ; gel permeation chromatography ; on-column interface ; co-solvent trapping ; gas chromatography ; large volume injection ; organophosphorus pesticides ; olive oil ; automation ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The robustness of an automated on-line GPC-GC-FPD method for the determination of Organophosphorus (OP) Pesticides in olive oil has been significantly improved, now allowing a routine operation. The original GPC-GC transfer technique employed a loop type interface with an early vapor exit and co-solvent trapping. Shooting, caused by boiling delay and malfunctioning of the solvent vapor exit during the transfer of the 3 mL solvent fraction to the retention gap, resulted in insufficient focusing of the OP-pesticides. In this interfacing concept, the GPC fraction is introduced directly into the carrier gas stream during a certain time interval using the Dualchrom pressure- and flow regulation, resulting in a very stable transfer. The interface now basically corresponds to an on-column interface with flow regulation. Via a Pyrex glass door behind the GC-oven door it can be seen that the liquid flow is broken up into alternating gas-liquid segments by the carrier gas flow during transfer. This avoids shooting in the retention gap and broadens the temperature range for successful transfer. By using a smaller sized GPC column the solvent fraction transferred was reduced to 1.3 mL. Methyl acetate/cyclopentane and the co-solvent n-nonane were selected for their lower boiling points. The modified method is very robust and has been applied to the analysis of 28 different OP-pesticides in olive oil with an overall detection limit of 0.002 mg/kg. Routinely 24 h of unattended operation is possible with a cycle time of 75 min.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 90
    Electronic Resource
    Electronic Resource
    Investigation into the Formation of Bubbles in Capillary Electrochromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 29-32 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrochromatography ; electroosmotic flow ; frit ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The formation of bubbles in capillary electrochromatography (CEC) is well documented: possible origins include Joule heating and variations in EOF velocity on passing from the stationary phase through the frit and into the open tube. Methods for the prevention of bubble formation are discussed which are confirmed by experimental results. Using frit lengths varying from 1 mm to 6 mm it is shown how frit length is directly related to the likelihood of bubble formation and how this is affected by applied voltage. It is shown that the change in applied voltage across a capillary affects the formation of bubbles and also that rebonding octadecylsilane (ODS) onto the silica frit after formation of the frit can minimize the formation of bubbles and how this effects the chromatography. A method is also described for increasing the robustness of silica capillaries using a column coupler along with modifications made to conventional capillary electrophoresis equipment to cater for CEC.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 91
    Electronic Resource
    Electronic Resource
    Determination of Dihydroxybenzenes in Plastic Food Packaging Materials and in Food Simulating Liquids Using Capillary Electrophoresis (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 39-42 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrophoresis ; CE ; chemical migration ; food contact plastics ; dihydroxybenzenes ; packaging ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A capillary electrophoresis method has been developed to determine 1,2-dihydroxybenzene and 1,3-dihydroxybenzene in the food simulants distilled water, 3% acetic acid, 15% ethanol, and olive oil. Both substances, used as monomers and additives to make food packaging plastics, could be analyzed within 15 min. The 1,4-dihydroxybenzene isomer was unretained and eluted with the electroosmotic flow, and so the CE method can give only a semi-quantitative estimate of this isomer if it is present as a migrant. The analytical recovery for the 1,2- and 1,3-isomers from spiked simulants was good at 87% to 98% except for 1,2-dihydroxybenzene which could only be recovered to the extent of 58% from olive oil. Calibration graphs were linear and the limit of detection for each substance was 0.6 mg/kg, which is well below migration limits for these substances. It is concluded that CE offers a rapid and reliable analysis for the control of migration from plastics intended for food contact which employ 1,2-dihydroxybenzene or 1,3-dihydroxybenzene during manufacture, and offers a screening method for 1,4-dihydroxybenzene migration.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 92
    Electronic Resource
    Electronic Resource
    Injection by Programmed Temperature Vaporization Injection (PTV) of Gaseous Samples for Gas Chromatography - Atomic Emission Spectrometry (GC-AED) (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 47-51 
    Details
    ISSN: 0935-6304
    Keywords: Programmed temperature vaporization (PTV) ; GC-AED ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Programmed temperature vaporization injection (PTV) coupled to gas chromatography and atomic emission detector (AED) has been studied for large volume injection of gaseous samples. As examples of the effectiveness of the technique, the results of the analysis of a series of headspace samples of foods such as garlic and onion, and of landfill gases are presented. The volumes of gaseous samples reconcentrated varied from a few milliliters up to liters depending on analyte dilution, through focusing onto a sorbent trap, then rapid liberation into the GC-AED system by programmed thermal desorption. Despite the high carrier gas flow rates associated with direct PTV-GC, AED performance and sensitivity were unaffected. The detailed elemental information obtained from the PTV-GC-AED analyses was confirmed using a PTV coupled to a gas chromatograph with ion trap detector mass spectrometer as detector (PTV-GC-ITD/MS).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 93
    Electronic Resource
    Electronic Resource
    Investigation into the Effects of Sample Dissolving Solvents and Sample Matrices on the Separations Obtained in Capillary Electrophoresis. Part II. MECC (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 55-58 
    Details
    ISSN: 0935-6304
    Keywords: Micellar electrokinetic capillary chromatography ; sample dissolving solvent ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 94
    Electronic Resource
    Electronic Resource
    Separation of Regioisomers of Substituted Bromoindoles of Pharmaceutical Interest by RP-HPLC and Capillary Electrophoresis Based on Interaction with Sulfobutyl Ether-β-cyclodextrin (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 59-62 
    Details
    ISSN: 0935-6304
    Keywords: Sulfobutyl ether-β-cyclodextrin ; micellar electrokinetic chromatography ; separation of regioisomers ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 95
    Electronic Resource
    Electronic Resource
    Determination of the Specific Migration of DEHP into Food Simulants Using High Performance Liquid Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 70-72 
    Details
    ISSN: 0935-6304
    Keywords: HPLC ; di(2-ethylhexyl) phthalate ; migration ; foods and food simulants ; PVC cling film ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 96
    Electronic Resource
    Electronic Resource
    Capillary Electrophoretic Identification of Commercial Gelling Agents (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 79-82 
    Details
    ISSN: 0935-6304
    Keywords: Capillary electrophoresis ; thickeners ; monosaccharides ; PMMA capillaries ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Gelling agents based on polysaccharides have become extremely important in the food industry. As more and more products like soups and sauces have become available in lyophilized form, thickeners have to be added to give a controlled consistency to the finished meal. A capillary electrophoretic method has been developed to investigate the monosaccharide composition of hydrolyzed thickeners. 2-Aminoanthracene was used as a derivatization reagent to allow sensitive fluorescence detection. This system was applied to a set of standard thickeners as well as to food samples.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 97
    Electronic Resource
    Electronic Resource
    GC Analysis of Organic Acids and Phenols Using On-Line Methylation with Trimethylsulfonium Hydroxide and PTV Solvent Split Large Volume Injection (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 83-88 
    Details
    ISSN: 0935-6304
    Keywords: Large volume injection ; programmed-temperature vaporizer ; organic acids ; phenols ; derivatization ; trimethylsulfonium hydroxide ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The combination of on-line methylation using trimethylsulfonium hydroxide with large volume injection of 100 μL was evaluated for the analysis of organic acids and phenols in water. Solvent split injection was applied with complete evaporation of the solvent before analytes were transferred onto the GC column. Despite complete solvent removal, losses were very low compared to conventional splitless injection even for volatile acidic compounds such as propionic acid and phenol. This is explained by intermediate formation of low volatility trimethylsulfonium salts of the analytes which were held in the injector for long evaporation times of up to 10 min, if the evaporation temperature was as low as 10°C. Using a simple liquid/liquid extraction procedure, volatile fatty acids, dicarboxylic acids, benzoic acids and phenols could be detected in 5 mL of water at concentrations of 0.04-0.1 μmol/L with GC/MS in full scan mode. Lactic, pyruvic, and also malonic acids could only be detected at higher levels because of their limited extractability from water as well as their poorer methylation yields. The method provides an easy way to sensitively detect acidic compounds of medium to high volatility in water. It was applied for screening of organic acids and phenols in batch cultures of anaerobic bacteria of which one example is shown.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 98
    Electronic Resource
    Electronic Resource
    Study on the Performance of Three Different Capillary Gas Chromatographic Analyses in the Evaluation of Milk Fat Purity (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 97-102 
    Details
    ISSN: 0935-6304
    Keywords: Capillary GC ; milk fat purity ; chemometrics ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The adulteration of milk fat with foreign fat has been and still is a major concern in the dairy industry. Milk fat purity is currently evaluated by triglyceride analysis by using the Official EU method. The detection limit of the various vegetable and animal fats ranges between 4 and 6%. This research was carried out to verify whether it is possible to decrease the detection limits of beef tallow, which is the most widely used adulterating animal fat. For this purpose, determinations of diglycerides and 3,5-cholestadiene, together with the Official EU method, were applied both to several samples of pure milk fat and to mixtures of milk fat with different percentages of beef tallow. The best results were obtained combining the data deriving from the three determinations by multivariate statistical techniques; in particular, the statistical model obtained by the UNEQ technique seems to be able to decrease the detection limit of beef tallow from 5.2 to 2%. The diglyceride and 3,5-cholestadiene evaluation, combined with the Official EU method for triglycerides, can be usefully applied both to detect small additions of beef tallow and to demonstrate the adulteration of milk fat samples showing results close to the detection limit of the official method.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 99
    Electronic Resource
    Electronic Resource
    Solid-phase Microextraction of Volatile Polar Compounds in Water (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 109-115 
    Details
    ISSN: 0935-6304
    Keywords: Solid-phase microextraction ; capillary gas chromatography ; volatile polar compounds ; water matrix ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---A method was developed for the analysis of volatile polar compounds in a water matrix using open cap vials Solid Phase Micro-Extraction (SPME) and Capillary Gas Chromatography (CGC). Both SPME techniques - direct sampling and headspace - were tested. Optimization of experimental conditions - exposure time, desorption time, with headspace SPME in addition the influence of the temperature and ionic strength of the sample solution on compound sorption, and finally GC response - were investigated. The analytes were extracted by directly immersing the 85 μm polyacrylate fiber in the aqueous sample or in the headspace. The linear range of the preconcentration process and the precision were examined. The amount of polar analytes sorbed on the fiber was determined and was found to be concentration dependent; it amounted to 0.014-0.64% in the concentration range of 0.00425-425 ppm studied in aqueous solution for direct sampling SPME and to 0.011-2.76% for solutions of concentration 0.0425-255 ppm for headspace SPME. The limits of determination were ascertained. Headspace SPME was applied to the analysis of real-life samples.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 100
    Electronic Resource
    Electronic Resource
    Analysis of Aliphatic Amines by Micellar Electrokinetic Chromatography (1999)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 126-128 
    Details
    ISSN: 0935-6304
    Keywords: Micellar electrokinetic chromatography ; capillary electrophoresis ; amines ; cyclodextrins ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...