Klaus Drysch

Metabolism of toluene in man: gas-chromatographic determination of o-, m- and p-cresol in urine

Complete separation of phenol, o-, m- and p-cresol was achieved by capillary gas-chromatography. Urinary concentrations of cresols were determined quantitatively in samples from 10 male workers exposed to toluene. Besides pcresol, o- and m-cresol were found to be urinary compounds in the case of the exposed group in contrast to normal persons. This finding was proved by gas-chromatography/mass spectrometry. The difference between both groups is significant. It is concluded that besides hippuric acid o-, m- and p-cresol are metabolites of toluene.

Cumulative effects of daily toluene exposure

SummaryTo study the elimination of toluene under irregular long-term exposure conditions, we investigated eight workmen who were exposed to concentrations of toluene between 184 ppm and 332 ppm in a plastic processing factory during 2 consecutive weeks. Besides the daily toluene concentrations in ambient air, the toluene concentrations in blood before and after the shifts were determined three times a week.The average concentrations in blood before the shift during the 2 weeks increased 10-fold and in some cases to 20 times the initial value. At average concentrations in the ambient air about the MAC-value the increase was found to be nearly the same. The relevance of these findings concerning the accumulation in other organs of the human body is discussed.

Stereometabolism of styrene in man: gas chromatographic determination of phenylethyleneglycol enantiomers and phenylethanol isomers in the urine of occupationally-exposed persons.

A gas Chromatographic procedure for the determination of phenylethyleneglycol enantiomers and phenylethanol isomers is described and applied to the investigation of urine samples from occupationally styrene-exposed workers (11 males, six females) and an unexposed control group. Phenylethyleneglycol enantiomers and 2-phenylethanol were present in the urine samples of exposed and unexposed individuals whereas 1-DL-phenylethanol was not found in control urine. The L/D enantiomer ratio of phenylethyleneglycol was found to be approximately 3 in the exposed group and 1.5 in the control group. Because of the close structural relation of these metabolites to the primarily formed epoxide, the results give further insight into the stereotoxicity of styrene in man

[Psychomotor responses under standardized trichloroethylene load (author's transl)].

Abstract20 volunteers were exposed for 4 hrs to a concentration of trichloroethylene in room air of 95 ppm. Before and after exposure the Wiener Detenninationsgerät, the Wiener Reaktionsgerät, and the motorische Leistungsserie (Schoppe) were used to perform 6 tests, each of which gave 15 measurements. A comparison with the results of a blank test which had been obtained 1 week before with the same volunteers under the same conditions, but without the use of trichloroethylene, yielded no statistically significant impairment of the psychomotorial function by trichloroethylene. Further investigations are being carried out.Zusammenfassung20 Versuchspersonen wurden 4 Std lang einer Trichloräthylenraumluftkonzentration von 95 ppm ausgesetzt. Vor Beginn und nach Beendigung der Exposition wurden am Wiener Determinationsgerät, am Wiener Reaktionsgerät und an der motorischen Leistungsserie (Schoppe) 6 Aufgaben gestellt und daraus je 15 Meßwerte gewonnen. Ein Vergleich mit den Ergebnissen eines Leerversuches, der eine Woche zuvor bei den gleichen Versuchspersonen unter gleichen Bedingungen, nur ohne Tri erzielt worden waren, ergab keine statistisch signifikante Beeinträchtigung der psychomotorischen Funktionen durch Trichloräthylen. Weiterführende Untersuchungen sind in Arbeit.20 volunteers were exposed for 4 hrs to a concentration of trichloroethylene in room air of 95 ppm. Before and after exposure the Wiener Determinationsgerät, the Wiener Reaktionsgerät, and the motorische Leistungsserie (Schoppe) were used to perform 6 tests, each of which gave 15 measurements. A comparison with the results of a blank test which had been obtained 1 week before with the same volunteers under the same conditions, but without the use of trichloroethylene, yielded no statistically significant impairment of the psychomotorial function by trichloroethylene. Further investigations are being carried out.

Bestimmung von freiem Pentachlorphenol in der Luft und im Blut durch leistungsfähige Routineverfahren

SummaryEfficient chromatographic procedures for the determination of free pentachlorophenol in air and in blood have been developed. Free pentachlorophenol from the indoor environment is preconcentrated in an impinger. Following a simple extraction, it is detected by high performance liquid chromatography without derivatisation. An alternate method is capillary gas chromatography of a suitable derivative. Unchanged pentachlorophenol in whole blood is similarly derivatised and determined quantitatively by capillary gas chromatography using an electron capture detector. The calibration curves of the described chromatographic methods were linear within the specified concentration range. Reproducibility of gas chromatographic separation remained unchanged during the whole research period. Owing to its relative simplicity, the described gas chromatographic method is advantageous for the biological monitoring of large collectives.ZusammenfassungFür die Bestimmung von freiem Pentachlorphenol in der Luft und im Blut wurden leistungsfähige chromatographische Routineverfahren ausgearbeitet. Für die Raumluftbestimmung wird Pentachlorphenol durch Einleiten von Luft in einer Vorlage angereichert und nach Aufarbeitung in freier Form durch Hochdruck-Flüssigkeits-Chromatographie quantitativ erfaßt. Alternativ kann die Analyse nach Derivatisierung durch Kapillar-Gaschromatographie erfolgen. Freies Pentachlorphenol im Vollblut wird nach Aufarbeitung und Derivatisierung durch Kapillar-Gaschromatographie in Verbindung mit dem Elektroneneinfang-Detektor quantitativ bestimmt. Bei den beschriebenen chromatographischen Methoden sind die Eichkurven über den angegebenen Konzentrationsbereich linear. Die gaschromatographische Trennung blieb über den gesamten Untersuchungszeitraum völlig reproduzierbar. Die problemlose Derivatisierung läßt die beschriebene gaschromatographische Methode in Verbindung mit einem automatischen Probengeber für das biological monitoring auch größerer Kollektive geeignet erscheinen.

Stereometabolism of styrene in man

Chiral styrene metabolites obtained during initial styrene exposure of test persons were determined in urine samples using capillary gas chromatography. A typical time-dependent urinary concentration profile of one person over a 49-h period is presented and compared with the results of a previous study of occupationally exposed workers and an unexposed control group. Maximum levels of excretion of all styrene metabolites were observed at about the end of a 9-h workshift. Forty hours after exposure, the L/D-ratio of mandelic acid had subsided to the initial value, and the L/D-ratio of phenylethylene glycol to a value equal or slightly above the initial value.

[EEG changes under standardized trichloroethylene load (author's transl)].

SummaryFrom 20 volunteers EEG were lead at hourly intervals telemetrically while exposed to 95 ppm trichloroethylene for 4 hrs. The same investigations were carried out without trichloroethylene. Compared with responses on other compounds we only found minimal changes.ZusammenfassungVon 20 Versuchspersonen wurden während einer 4-stündigen Exposition von 95 ppm Trichloräthylen EEGs in stündlichen Abständen telemetrisch abgeleitet. Die gleichen Untersuchungen wurden an einem Trifreien Kontrolltag durchgeführt. Im Gegensatz zu vergleichbaren Reaktionen auf andere Schadstoffe fanden sich hier im Verlauf der Exposition nur unbedeutende Veränderungen.