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
  • 1
    Electronic Resource
    Electronic Resource
    Gaschromatographische Bestimmung der Ameisensäure im Blut nach Überführung in Kohlenmonoxid (1977)
    Springer
    Microchimica acta 68 (1977), S. 405-412 
    Details
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A reliable and sensitive gaschromatographic method for the determination of formic acid in blood is described. By steam distillation formic acid is separated from blood. Then by means of concentrated sulfuric acid, formic acid is converted into carbon monoxide. This is then separated by gaschromatography, reduced to methane catalytically and determined with a flame ionisation detector. The mean concentration of formic acid in blood of a group of normal persons (n=12) was found to be 3,7±2,4 mg/l.
    Notes: Zusammenfassung Eine analytisch zuverlässige und empfindliche gaschromatographische Methode zur Bestimmung von Ameisensäure im Blut wurde beschrieben. Dabei wird die Ameisensäure durch Wasserdampf-destillation aus dem Blut abgetrennt und durch Einwirkung konzentrierter Schwefelsäure in Kohlenmonoxid übergeführt. Dieses wird gaschromatographisch von anderen Bestandteilen abgetrennt, katalytisch zu Methan reduziert und als solches im Flammenioni-sationsdetektor bestimmt. Bei einem Kollektiv von Normalpersonen (n=12) wurde eine mittlere Ameisensäurekonzentration von 3,7±2,4 mg/l im Blut gefunden.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01196226
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Influence of dichloromethane on the disappearance rate of ethanol in the blood of rats (1974)
    Springer
    International archives of occupational and environmental health 33 (1974), S. 231-236 
    Details
    ISSN: 1432-1246
    Keywords: Halogenated hydrocarbons ; Ethanol ; Metabolism ; Disappearance rate ; Animal experiments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 24 Albino-Wistar rats were exposed to dichloromethane-vapours in a concentration of 4200 ppm over a period of 4 hrs after intraperitoneal application of 2.0 g ethanol per kilogram body weight. The disappearance rate of ethanol was measured between the 80th and 240th min after the beginning of the exposure. In comparison to a control group of 24 other rats not exposed to dichloromethane the blood ethanol concentrations turned out to be significantly higher, although an influence of dichloromethane on the ethanol metabolism could not be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00538921
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Chronische lösungsmittelbelastung am arbeitsplatz (1976)
    Springer
    International archives of occupational and environmental health 36 (1976), S. 287-297 
    Details
    ISSN: 1432-1246
    Keywords: Toluene ; Hippuric acid ; Thin-layer scanning ; Urine ; Printing works ; Toluol ; Hippursäure ; Chromatogramm-Spektralphotometrie ; Harn ; Tiefdruckbetrieb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird eine dünnschichtchromatographisch-densitometrische Methode zur Bestimmung der Hippursäurekonzentration im menschlichen Urin beschrieben. Ihre unter den Bedingungen der statistischen Qualitätskontrolle ermittelte Genauigkeit beträgt 6,85%. Die Wiederauffindungsraten lagen zwischen 98,1 und 104,5%. Diese Zuverlässigkeitskriterien werden mit der auf Pagnotto zurückgehenden UV-spektrometrischen Bestimmungsmethode verglichen. Die Selektivität der Methode erlaubt es u.a., die bei einer Mischexposition gegenüber Toluol und Xylolen im Harn auftretenden Tolursäuren von Hippursaure abzutrennen und zu bestimmen. Die dünnschichtchromatographisch bestimmte mittlere Hippursäureausscheidung eines Normal-Kollektivs (n = 30) betrug 0, 79 g/l. Ein Kollektiv von toluolexponierten Arbeitern wurde zu Schichtbeginn und gegen Schichtende hinsichtlich seiner Hippursäureausscheidung untersucht. Bei einer mittleren Toluolkonzentration in der Luft von 27 ppm ergab sich eine densitometrisch bestimmte mittlere Hippursäureausscheidung von
    Notes: Summary A thin-layer chromatographic-densitometric method for determining hippuric acid in human urine is described. Under conditions of statistical quality control the precision of the method is 6.85%. The rate of recovery is 98.1–104.5%. The selectivity of the method enables separation and determination of, among others, hippuric acid from methyl-hippuric acids. These acids are eliminated in the urine of people exposed to toluene as well as to xylenes. The criteria for reliability are compared with those of the UV-spectrometric method tracing back to Pagnotto. The average concentration of hippuric acid as determined by thin-layer chromatography of a group of normal persons (n = 30) was 0.79 g/l. A group of employees exposed to toluene was examined according to their elimination of hippuric acid at the beginning and the end of their shift. An average concentration of 27 ppm of toluene in the air caused an average elimination of hippuric acid in urine of 2.04 g/l which was determined densitometrically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409358
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Occupational chronic exposure to organic solvents (1979)
    Springer
    International archives of occupational and environmental health 42 (1979), S. 241-249 
    Details
    ISSN: 1432-1246
    Keywords: Methanol ; Formic acid ; Metabolism ; Printing ; Health supervision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study was carried out among 20 workers employed in a printing, office at three different work places (methanol concentration: 85, 101, and 134 ppm) to determine whether the concentration of formic acid in blood or urine and the methanol content of alveolar air permit the estimation of methanol exposure. For this purpose blood, urine, and end expiratory air were collected at the beginning and the end of the shift. For comparison formic acid concentrations were determined in the morning and in the afternoon in blood and urine of 36 and 15 control persons, respectively. The concentration of formic acid in blood increased significantly from 3.2 ± 2.4 mg/l before to 7.9 ± 3.2 mg/l after the shift in the exposed workers (mean increase 4.7 ± 3.8 mg/l). The corresponding concentrations in urine were 13.1 ± 3.9 mg/l and 20.2 ± 7 mg/l, respectively, with a mean increase of 7.1 ± 5.3 mg/l. This difference is also significant. On the contrary, in the control groups there was a small but significant decrease of formic acid concentration in blood from 5.6 ±4.5 mg/l in the morning to 4.9 ± 4.2 mg/l in the afternoon. In urine, the formic acid concentrations in the morning (11.9 ± 6.4 mg/l) and in the afternoon (11.7 ±5.6 mg/l) were not significantly different. The increase of formic acid concentration in blood during the shift is the most useful parameter for monitoring methanol exposed persons. In contrast determinations of methanol concentrations in the ambient air or in the exhaled air are only crude estimates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377778
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Chronische Lösungsmittelbelastung am Arbeitsplatz (1973)
    Springer
    International archives of occupational and environmental health 31 (1973), S. 1-8 
    Details
    ISSN: 1432-1246
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Unter dem Aspekt einer Prävention beruflich bedingter Gesundheitsschäden durch eine Langzeitexposition gegenüber subtoxischen Konzentrationen organischer Lösungsmittel werden gaschromatographische Methoden zur quantitativen Bestimmung von Benzol und Toluol in Luft- und Blutproben vorgestellt. Die Blutanalyse bedient sieh dabei des Verfahrens der sogenannten Dampfraumanalyse. Bei Bruttoretentionszeiten von 1,2 min für Benzol und 2 min für Toluol lassen sich die untersuchten aromatischen Lösungsmittel frei von störenden Substanzen erfassen. Eine hohe analytische Zuverlässigkeit und sehr geringe Nachweisgrenzen ermöglichen die arbeitsmedizinische überwachung auch gering Exponierter. Der Arbeitsaufwand ist minimal, so da\ sich das Verfahren auch für die routinemä\ige Serienanalyse eignet.
    Notes: Summary With regard to the hygienic risk of workers chronically exposed to organic solvents the estimation of xenometabolically produced substances is now and then insufficient. Sometimes it may be necessary to determine the organic solvents themselves in biological materials, especially in blood. However, the methods now available are too insensitive to detect lower concentrations. To complete the diagnostic program in the health supervision of workers exposed to lower concentrations of benzene and toluene gas chromatographic methods for the determination of these substances in air and in blood are presented. The timesparing analysis of blood samples is basing on the head space technic. The total retention time for benzene is 1.2 min, that of toluene is 2.0 min. There is no disturbing background in the gas chromatograms, neither for benzene nor toluene. The accuracy expressed as the recovery amounts to about 100%. The precision (v=1.5 to 4.1%) is satisfactory. The detection limits for the two organic solvents are very low both in air and in blood. So the method is suited for the health supervision even of low exposed persons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00538968
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Occupational chronic exposure to organic solvents (1979)
    Springer
    International archives of occupational and environmental health 43 (1979), S. 145-150 
    Details
    ISSN: 1432-1246
    Keywords: Xylenes ; Ethylbenzene ; Metabolism in man ; 2-Ethylphenol ; Synergism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four female assistants using a mixture of xylenes and ethylbenzeneas solvent in a histology laboratory were examined according to the concentrations of solvents in blood and the excretion of phenolic compounds in urine during 24 h. The average concentrations of (m+p)-xylene and ethylbenzene in air were between 56 and 68 ppm and 34 and 41 ppm respectively. It is shown that about 1.1–1.4% of the retained ethylbenzene is metabolized to 2-ethyl-phenol. 2,4-Dimethylphenol as a metabolite of m-xylene could not be detected. It is supposed that a competitive reaction mechanism between xylenes and ethylbenzene takes place preventing m-xylene from oxidation at the aromatic nucleus. Possible carcinogenic properties of epoxides formed as intermediates must be considered.-The estimation of threshold values for the concentration of solvents in blood was attempted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378152
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Chronische Lösungsmittelbelastung am Arbeitsplatz (1973)
    Springer
    International archives of occupational and environmental health 31 (1973), S. 265-276 
    Details
    ISSN: 1432-1246
    Keywords: Toluene ; Hippuric acid ; Printing-works ; Metabolism ; Organic solvents ; Supervision ; Toluol ; HippursÄure ; Tiefdruckbetrieb ; Metabolismus ; Org. Lösungsmittel ; überwachungsuntersuchung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An einem beruflich toluolexponierten Kollektiv einer Druckerei (n=94) wurde geprüft, welche Beziehungen zwischen der Toluolkonzentration in der Raumluft, dem Toluolspiegel im Blut und der HippursÄureausscheidung im Harn bestehen. Die Toluolanalysen in der Luft und im Blut erfolgten gaschromatographisch, die HippursÄurebestimmungen spektralphotometrisch. Als obere Normgrenze der Toluolkonzentration im Blut (errechnet aus einem nicht lösungsmittelbelasteten Vergleichskollektiv; n=30) ergab sich 15 Μg Toluol pro 100 ml Blut. Bei den belasteten Probanden fand sich eine enge Beziehung zwischen der Toluolkonzentration im Blut und der in der Raumluft, wÄhrend sich eine AbhÄngigkeit der HippursÄureausscheidung im Harn von der Toluolkonzentration im Blut oder in der Raumluft statistisch nicht sichern lie\. Gleichzeitig durchgeführte Phenolbestimmungen im Harn zeigten dagegen eine hochsignifikante Korrelation mit der HippursÄureausscheidung im Harn bei den toluolbelasteten Probanden auf. Damit mu\ die Eignung von Phenolbestimmungen im Harn zur überwachung Benzolexponierter bei gleichzeitiger Toluolbelastung in Frage gestellt werden. Für die überwachung Toluolexponierter wird neben der HippursÄurebestimmung im Harn eine Toluolanalyse im Blut als Kriterium für die individuelle Belastung empfohlen.
    Notes: Summary The relationship between the toluene concentrations in blood and the excretion rates of hippuric acid was investigated in 94 printing-workers occupationally exposed to toluene. Toluene in air and in blood was determined by gaschromatographic analysis, the hippuric acid by spectroscopy. In a control group (n=30) the normal upper limit of the toluene concentration in blood was 15 Μg toluene/100 ml blood. In the occupationally exposed group there was a good correlation between the toluene concentrations in air and in blood. But the excretion rates of hippuric acid had no dependence upon the concentrations of toluene in air or in blood. The levels of phenols in the urine were determined in the same workers and were closely correlated with the excretion of hippuric acid. Therefore supervision of workers exposed simultaneously to benzene and toluene by determination of phenols in the urine seems to be of little value. The determination of toluene in blood is recommended for the supervision of workers exposed to toluene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00539031
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Chronische Lösungsmittelbelastung am Arbeitsplatz (1975)
    Springer
    International archives of occupational and environmental health 34 (1975), S. 199-207 
    Details
    ISSN: 1432-1246
    Keywords: Hippuric Acid ; Gas Chromatography ; Serum ; HippursÄure ; Gaschromatographie ; Serum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird eine gaschromatographische Methode zur Bestimmung der HippursÄurekonzentration in menschlichem Serum beschrieben. Die analytische ZuverlÄssigkeit dieser Methode erfüllt die Anforderungen der statistischen QualitÄtskontrolle. Die Wiederauffindungsraten lagen zwischen 97,5 und 104 %, die VariabilitÄtskoeffizienten zwischen 3,3 und 3,8 %. Die Nachweisgrenze von rund 0,6 mg HippursÄure/1 Serum ermöglicht es, nicht nur bei toluolbelasteten Arbeitern, sondern auch bei Normalpersonen den HippursÄuregehalt im Serum zu bestimmen. Die praktische Anwendbarkeit dieser Methode wird an einer kleinen Gruppe von unbelasteten Personen (n=8) sowie an einem Kollektiv von toluolexponierten Arbeitnehmern (n=98) demonstriert.
    Notes: Summary A gas chromatographic method for determining hippuric acid in human serum is described. The analytical reliability of this method fulfills the criteria of statistical quality control. The rate of recovery is 97.5 to 104 %, the variability coefficients lie between 3.3 and 3.8 %. The detection limit of about 0.6 mg hippuric acid/1 serum enables determination of the concentration of hippuric acid in the serum of employees exposed to toluene as well as that of normal persons. The practical applicability of this method is demonstrated in a small group of unexposed persons (n=8) and a group of employees exposed to toluene (n=98).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01371741
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Occupational chronic exposure to organic solvents (1979)
    Springer
    International archives of occupational and environmental health 43 (1979), S. 63-67 
    Details
    ISSN: 1432-1246
    Keywords: Toluene ; Benzene ; Cresols ; Phenol ; Urine ; Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A group of printing workers (n = 34) exposed to toluene was examined according to the concentrations of hippuric acid, phenol, o-cresol, and (m+p)-cresol in urine. The average concentration in the air of the workroom was 23 ppm. It is shown that, besides hippuric acid, small amounts $$(\bar x = 1.1{\text{ }}mg/l)$$ of o-cresol. which is not a normal constituent of urine, were formed from toluene. The occurrence of o-cresol could be proved by mass spectrometry. On account of the small amounts of benzene present in industrially used toluene—in this case 0.025%—the average concentration of phenol in urine of the exposed group was significantly higher statistically $$(\bar x = 7.6 \pm {\text{ 4}}{\text{.3 }}mg/l)$$ than in urine from the controls $$(\bar x = 5.3 \pm {\text{ 2}}{\text{.0 }}mg/l; n = 28)$$ .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00454281
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Chronische lösungsmittelbelastung am arbeitsplatz (1979)
    Springer
    International archives of occupational and environmental health 42 (1979), S. 257-268 
    Details
    ISSN: 1432-1246
    Keywords: Phenol ; Cresols ; Gas chromatography ; High pressure liquid chromatography ; Photometry ; Urine ; Phenol ; Kresole ; Gaschromatographie ; Hochdruckflüssigkeitschromatographie ; Photometrie ; Harn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine gaschromatographische und eine hochdruckflüssigkeitschromatographische Methode zur Bestimmung von Phenol und Kresolen im Harn wind beschrieben. Phenol wind in beiden Fällen selektiv erfaßt. o-, m- und p-Kresol wird beschrieben. Phenol wind in beiden Fällen selektiv erfaßt. o-, m- und p-Kresol werden hochdruckflüssigkeitschromatographisch nicht getrennt. Gaschromatographisch gelingt die Abtrennung von o-Kresol. Aufgrund der speziellen Probenaufbereitung sind beide Verfahren sehr empfindlich. Die Nachweisgrenzen liegen zwischen 0,2 und 1,3 mg/l. 24-h-Harne eines Normalkollektivs (n = 30) werden untersucht (xPhenol = 4,6 mg/l; xp-Kresol = 45,7 bzw. 52,6 mg/l). Die Ergebnisse werden mit denen eines photometrischen Verfahrens verglichen.
    Notes: Summary Gas chromatographic and high pressure liquid chromatographic methods for the determination of phenol and cresols in urine are described. In both cases phenol is determined specifically; o-, m- und p-cresols are not separated by high pressure liquid chromatography. However, o-cresole is separated by gas chromatography. On account of the special preparation of urine samples both methods are very sensitive. The detection limits lie between 0.2 and 1.3 mg/l. 24-h samples of normal urines (n = 30) are analysed (xphenol = 4.6 mg/l; xp-cresol = 45.7 mg/l, respectively 52.6 mg/l). These results are compared with those of a photometric method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377780
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...