Trichloroethene, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane and tetrachloroethene – Determination of trichloroacetic acid in urine using headspace-gas chromatography-mass spectrometry [Biomonitoring Methods, 2017]

Trichloroacetic acid is a metabolite of several chlorinated hydrocarbons which are often used as solvents, such as 1,1,1‐trichloroethane, 1,1,2,2‐tetrachloroethane, tetrachloroethene and above all trichloroethene. The described method enables the determination of trichloroacetic acid (TCA) in urine and is based on the quantitative, thermolytic degradation of TCA into carbon dioxide and chloroform (trichloromethane) in an aqueous solution. The analyte is chloroform, which can be quantified using headspace‐gas chromatography and a mass selective detector in the Selected‐Ion‐Monitoring‐mode. For quantitation, a calibration is carried out using standard solutions in pooled urine or water which are processed and analysed in the same way as the samples. The validation of the procedure showed a precision in the range of 4.0 to 5.5%. Mean accuracy ranged from 95 to 118%. LOQ was found to be 0.03 mg TCA per liter urine.