Objective To establish a headspace-gas chromatography-mass spectrometry (HS-GC-MS) method for determining trichloroacetic acid (TCA) in urine that can solve the interference of chloroform.
Methods According to the principle that trichloroacetic acid transforms into chloroform after heating and decarboxylation in a water bath, the HS-GCMS method was used to detect the peak area of chloroform before and after the water bath of the sample, and the accurate concentration of TCA was calculated according to the difference in peak area.
Results The method was used to determine TCA in urine, and it showed good linearity in the range of 0.01-50 mg/L, with a correlation coefficient of 0.999 9, a detection limit of 0.2 μg/L, a recovery rate of 96.8%-100.4%, and a relative standard deviation of 1.5%-2.3%. The sample can be stored at room temperature, 4 ℃, or-25 ℃ for 14 days without degradation. When chloroform was less than 10 mg/L, there was no interference with the determination.
Conclusions The method is simple, fast, and accurate and is suitable for determining TCA in the urine of occupational populations and poisoned patients.
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