Determination of 2,2,2-trichloroethanol in plasma and urine by ion-exclusion chromatography

A simple and rapid chromatographic method has been developed for the determination of 2,2,2-trichloroethanol (TCEOH) and its glucuronide in plasma and urine. A glass column (150 x 6.6 mm i.d.) packed with Aminex A-5 cation-exchange resin (potassium form) following the slurry method was used as the analytical column, and an admixture of 10 mmol l-1 potassium sulfate and 10 mmol l-1 potassium hydroxide solution as the eluent (pH 12.2). Diluted plasma samples and urine samples were directly injected into the chromatograph through a 0.45 micron membrane filter without deproteinization. The amount of TCEOH conjugated to glucuronide was determined following treatment with beta-glucuronidase (200 U) for 30 min at 37 degrees C. This allowed the concentration of free, total, and conjugated TCEOH to be determined. The calibration graph was rectilinear from 5 to 500 mg l-1 of TCEOH, with a detection limit of 3 mg l-1, 2 sigma, being the signal-to-noise ratio. The analytical recovery of TCEOH, obtained by analysing spiked plasma and urine samples, was in the range 98.4-102% and the relative standard deviation was less than 3.5%.