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Biomedical subjects

H Weichardt

Publications and source records attributed to H Weichardt.

At least 19 recordsLinked to original sources
PubMed1984

Styrene metabolism in man: gas chromatographic separation of mandelic acid enantiomers in the urine of exposed persons.

D- and L-mandelic acid are separated by gas chromatography as isopropyl ester or isopropyl ester-isopropyl urethane on capillary columns, coated with Chirasil -Val. For its determination in urine the isopropyl ester procedure gives better results because other components of the urine do not cause interference. Thus D- and L-mandelic acid in the urine of exposed workers could be detected and verified by means of GC/MS. Occupational styrene exposure near the MAK-value (100 ppm) results in a L/D-enantiomer-ratio in urine of nearly 1.5.

Chromatography, Gas↗
PubMed1980

[Infrared spectrometry and gas chromatography for determination of halothane in operation rooms (author's transl)].

Chronic halothane intoxication is a health hazard to anaesthetic personnel and requires permanent control of the degree of exposure. Two different methods are described: a continuous infrared spectrometric and an intermittent gas chromatographic determination of airborne halothane. An elaborate instruction for the measuring procedure is given; calibration techniques and detection limits are discussed. Data from operating rooms with different security equipment are listed. For determining the total burden gas chromatography is the method of choice, as the concentration range to be detected is rather low in general. In addition infrared spectrometric concentration monitoring gives valuable information about concentration peaks caused by typical handling in an operation room.

Air Pollutants↗
PubMed1979

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 p-cresol, 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 beside hippuric acid o-, m- and p-cresol are metabolites of toluene.

Biotransformation↗
PubMed1979

[Quantitative analysis of L-hydroxyproline in human biological material by gas-chromatography (author's transl)].

Quantitative amino acid analysis by gas chromatography was applied to the determination of 4-hydroxy-L-proline in biological material. After addition of a known amount of allo-4-hydroxy-D-proline, quantitative analysis of 4-hydroxy-L-proline can be performed by gas chromatographic separation of the amino acid enantiomers; since the standard and sample have identical chemical behaviour, they respond identically during derivatization. The accuracy, reproducibility, and sample requirement of this procedure are more advantageous than those of hitherto existing methods. This study is also an example of the application of chiral stationary phases, which permit the simultaneous separation of amino acids and amino acid enantiomers.

Chromatography, Gas↗
PubMed1978

[Chromosome studies on trichloroethylene workers (author's transl)].

On the basis of lymphocyte cultures, chromosome studies were carried out on 28 degreasers under different trichloroethylene load. Nine of these cases showed pathological rates of hypodiploid cells, but otherwise normal caryotypes; one case had a caryotype 47,XY,+mar (small metacentric extrachromosome). In these nine cases the trichloroethylene load, but not the exposure periods on the working place were significantly higher than in the control group.

Adult↗
PubMed1976

[Eberhard Gross].

Explore the source record for details and available documents.

Germany, West↗
PubMed1975

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

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.

Adult↗