US EPA

707840 

Journal Article 

Simple determination of trichloroacetic acid in urine using head space gas chromatography: a suitable method for monitoring exposure to trichloroethylene 

Senft, V 

1985 

Yes 

Journal of Chromatography A
ISSN: 0021-9673
EISSN: 1873-3778 

NIOSH/00144557 

337 

1 

126-130 

English 

3980641 

A method was developed for determining trichloroacetic-acid (76039) (TCA) in urine by head space gas chromatography (GC). Urine samples from persons exposed to trichloroethylene (79016) were placed into a flask with n-butanol and heated for 75 minutes at 90 degrees-C. Heating of urine in a closed flask caused decarboxylation of TCA to chloroform; the flask was maintained at 45 degrees. A sample of the gas phase was taken and injected into the GC column. Decarboxylation of TCA was determined by head space analysis and evaluated by comparison with an internal standard. Precision and relative recovery of the method were verified by ten fold repetition of the determination. Chloroform peaks increased during the first 45 minutes of decarboxylation and reached a maximum at about 60 minutes. Head space analysis was compared with photometric methods and the methods were equivalent. The sensitivity of the method was about 2 milligrams per liter. The author concludes that the method is simple and does not require electron capture detection. The procedure can be used for monitoring worker exposures to trichloroethylene.