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  • General Chemistry  (51)
  • Analytical Chemistry and Spectroscopy  (18)
  • Life Sciences  (6)
  • 1
    ISSN: 0269-3879
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: A high-performance liquid chromatographic (HPLC) assay method has been developed for the quantitative determination of iothalamate and p-aminohippuric acid (PAH) concentrations in serum and urine samples in the male rat. Glomerular filtration rate (GFR) was measured as clearance of iothalamate, while effective renal blood flow (ERBF) was measured as clearance of PAH. The method is simple, rapid and sensitive and detects iothalamate and PAH in rat serum and urine following administration of bolus doses and continuous infusions of iothalamate and PAH. Samples of serum and urine were deproteinized with two volumes of acetonitrile containing the internal standard, and an aliquot chromatographed on a C18 reversed-phase column. The mobile phase was comprised of 0.1 M sodium phosphate with 1.2 mM tetrabutylammonium phosphate: methanol, 85:15 (v/v), at a flow rate of 1.0 mL/min. The analytical column eluate was monitored with a UV detector at 254 nm with quantitation achieved using peak-height ratios. The precision of the method was 6.6 and 3.6% for iothalamate in serum and urine, and 5.6 and 4.9% for PAH in serum and urine, respectively. The lower limit of quantitation was 0.63 μg/mL for iothalamate and 1.25 μg/mL for PAH in serum, and 3.1 μg/mL for iothalamate and 1.5 μg/mL for PAH in urine. Recovery of iothalamate from serum and urine was 99.9 and 93.5%, respectively. Recovery of PAH from serum and urine was 99.8 and 92.6%, respectively.The present study demonstrated that non-radioactive iothalamate and PAH can be measured simultaneously using a HPLC assay to measure GFR and ERBF in the male rat.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 3 (1989), S. 180-182 
    ISSN: 0269-3879
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: A simple, accurate and precise procedure for the quantitation of itazigrel (a potent lipophilic inhibitor of collagen and arachidonic acid-induced aggregation being studied for its effects on peripheral vascular disease) from granulated rodent diet is presented. The drug was extracted from rodent diet using methanol + water (80:20) following dissolution of the diet in water. Samples of the supernatant were injected into the HPLC and the eluent was monitored with a fluorescent detector (λex = 320 and λem = 430) to achieve analytical specificity. Interday coefficients of variation of the calibration curve slope were ±6% on standards between 0 and 1000 μg/g. Potency and homogeneity of the drug spiked diet prepared over a 1 year interval at 70,200 and 600 μg/g was 99.3 ± 2.5%, 100 ± 1.8%, and 101 ± 1.9% of label, respectively. Samples prepared for chromatography were stable for 24 h at 20°C, and drug in diet was stable for 102 days when protected from light and stored at 20°C.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 15 (1988), S. 553-564 
    ISSN: 0887-6134
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Capillary column isobutane chemical ionization was found to be an excellent method for the mass spectral characterization of mustard, other sulfur vesicants and related compounds. Interpretation of [M + H]+ and fragmentation ion information afforded by this technique enabled the identification of many previously unreported mustard impurities. The developed methodology was applied to the analysis of an Iran/Iraq soil sample suspected to have been contaminated with mustard. Mustard and 17 other mustard related impurities were identified and characterized in this sample under electron impact and isobutane chemical ionization conditions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 639-643 
    ISSN: 0935-6304
    Schlagwort(e): Cyclodextrin ; Halowax ; hexachloronaphthalene ; PCN ; polychlorinated naphthalenes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---No abstract
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 15 (1992), S. 615-619 
    ISSN: 0935-6304
    Schlagwort(e): Capillary GC ; Splitless injection ; Electronic pressure control (EPC) ; Nitrogen - phosphorus detector (NPD) ; Flame photometric detector (FPD) ; Flame ionization detector (FID) ; Programmable cool on-column injection ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: HP 5890 Series II Gas Chromatographs are equipped with prototype hardware enabling electronic pressure programming of all detector and carrier gases. A method of using electronic pressure control (EPC) to optimize detector performance (sensitivity, selectivity, and baseline stability) is demonstrated. With EPC, sample introduction, column separation, and detector performance can be optimized simultaneously without the classical trade-offs in performance. An example is also presented of the use of a new automated system which enables cool on-column injection into 250 or 320 μm columns without the need for a retention gap.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 17 (1994), S. 203-211 
    ISSN: 0935-6304
    Schlagwort(e): Simulated distillation ; Boiling point distribution ; Element-specific detectors ; Carbon number distribution ; Petroleum ; Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Information about the boiling point distribution of petroleum and its products is obtained either by actual distillation, or by analyses designed to simulate the distillation process. These analytical techniques are called simulated distillations. Simulated distillations are most often performed by gas or supercritical fluid chromatography. This paper reviews the use of gas and supercritical fluid chromatography for simulated distillation, and the development of element-specific detection coupled with these analyses.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    ISSN: 1434-193X
    Schlagwort(e): Indiumallyl compounds ; Vinylcyclopropanes ; α,β-Unsaturated carbonyl compounds ; Diastereoselectivity ; Dibenzylideneacetone ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---Allylindium reagents, prepared from excess allylic halide (Br or I) and indium metal, react with α,β-unsaturated ketones and aldehydes to give, after aerobic acidic workup, homoallyl-substituted vinylcyclopropanes. This process was explored and developed after a chance discovery arising from a side reaction in an attempted Pd-catalysed process. The structure of the cyclopropane arising from the reaction of bis(p-chlorobenzylidine)acetone was confirmed by X-ray crystallography. Whilst bis-α,β-unsaturated ketones give rise to a single homoallylcyclopropane species, α,β-unsaturated ketones and aldehydes give diastereomeric mixtures whose relative stereochemistry were assigned by NOE experiments. Crotylindium reagents react with good to perfect regioselectivity to afford tetrasubstituted cyclopropanes but prenylindium reagents fail to generate the analogous pentasubstituted rings.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1434-193X
    Schlagwort(e): Indium ; Vinylcyclopropanes ; Ring closing metathesis ; Norcarenes ; Kinetic diastereoselection ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---Homoallyl-substituted vinyl cyclopropanes 1a-c, which are readily prepared by reaction of allylindium reagents with α,β-unsaturated ketones and aldehydes, undergo Ru-catalysed RCM reactions with Grubbs catalyst to give [4.1.0]bicyclooct-2-ene (norcarene) type bicyclic products. Noncyclisable ‘trans’ homoallyl-substituted vinyl cyclopropanes 1b and 1c are separated from their ‘cis’ diastereomers by RCM to 5b and 5c - but only with moderate efficiency due to a competing homo-cross metathesis (‘dimerisation’) to give 7b and 7c, respectively. However, the four diastereomers of the (homoallyl)distyrylcyclopropane 14a obtained from indium-mediated reaction of dibenzylideneacetone and crotyl bromide undergo remarkable kinetic diastereoselection in their RCM reactions to give a 4,7-dimethyl[4.1.0]bicyclohept-2-ene-type product 15a. This process allows recovery of a single diastereomer (〉 95%) of 14a without dimerisation being a significant side reaction. Furthermore, the RCM product 15a is obtained rich in one diastereomer (ca. 90%). The kinetic diastereoselection and lack of dimerisation can be rationalised by considering developing transannular interactions and a pseudo-A1,3 strain model.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1434-1948
    Schlagwort(e): Coordination modes ; Cyclophanes ; Macrocycles ; Sandwich complexes ; Solid-state structures ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A novel mode of containment for metal ions which participate in longer-range interactions with aryl rings (≥ 2.5 Å) is demonstrated in the preorganized cylindrical host 1. Three equatorial sulfur atoms in 1 hold metals in a trigonal planar ligand field between two apical benzene centroids at an M-Ar distance of about 3 Å. Evidence of an interaction between the π electrons and the metals is gained by 1H NMR spectroscopy of the complexes, and support for the general description of metal-arene contacts in the 2.5-3.5 Å range as ‘‘bonds’’ is derived from a statistical study of η6-coordination in the solid state. Crystal structures of [Ag(1)]BF4 and [Cu(1)]BF4 confirm the first examples of arene AgI and CuI sandwich complexation and indeed the only structurally characterized CuI-aryl centroid interaction. The two isomeric tris-sulfoxides derived from 1 show less tendency to interact with metals ions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1434-1948
    Schlagwort(e): Chirality ; Ruthenium ; Chiral resolution ; Nitrogen heterocycles ; Carbonyl complexes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A range of chiral building blocks of the type Δ- or Λ-[Ru(pp)2(CO)2]2+ {pp = bidentate ligands bpy (2,2′-bipyridine), phen (1,10-phenanthroline) and Me2bpy (4,4′-dimethyl-2,2′-bipyridine)} have been synthesized, and their enantiomeric purity and absolute configurations determined by CD and NMR studies. Decarbonylation using trimethylamine oxide in the presence of the respective pp ligand at room temperature produced the corresponding tris(bidentate) species [Ru(pp)3]2+ with retention of configuration at the ruthenium(II) centre. A general chromatographic technique for resolution of tris-homoleptic complexes of the type [Ru(pp)3]2+ was investigated, with the absolute configurations of the resolved complexes confirmed by CD studies, and the X-ray structural analyses of Δ-(-)-[Ru(Me2bpy)3]{(-)-O,O′-dibenzoyl-L-tartrate} and Λ-(+)-[Ru(phen)3]{(+)-O,O′-di-4-toluoyl-D-tartrate}. Resolution is also reported for the analogous species containing three potential bridging ligands, [Ru(bpm)3]2+ and [Ru(HAT)3]2+ (bpm = 2,2′-bipyrimidine; HAT = 1,4,5,8,9,12-hexaazatriphenylene). The versatility of the chromatographic procedure was demonstrated by the resolution of a series of bis-heteroleptic complexes [Ru(pp)2(pp′)]2+ {pp′ = dpq (dipyrido[3,2-d:2,3′-f]quinoxaline), dpqc (dipyrido[3,2-a:2,3-d]-6,7,8,9-tetrahydrophenazine), and dppz {dipyrido[3,2-a:2,3′-d]phenazine)}.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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