Gas chromatographic-mass spectrometric determination of chlorophenols in the urine of sawmill workers with past use of chlorophenol-containing anti-stain agents

The aim of this work was to establish whether workers at sawmills where chlorophenol-containing anti-stain agents had been previously used were still exposed to chlorophenols. A gas chromatographic-mass spectrometric (GC-MS) procedure for the determination of chlorophenols in urine was developed. Chlorophenols were determined from hydrolysed urine as acetylated derivatives and determined by GC-MS using selected ion monitoring (SIM). Isolation of the chlorophenols with toluene gave the best extraction efficiencies (65-119%). Stability tests at -20 degrees C showed no degradation of the chlorophenols studied during 6 months. The limit of quantification was 3.6 ng mg-1 creatinine for 2,4,6-trichlorophenol, 5.5 ng mg-1 for 2,3,4,6-tetrachlorophenol and 3.6 ng mg-1 for pentachlorophenol. Traces of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol were found both in previously exposed workers and in non-exposed controls, the urinary concentrations ranging from 1.1 to 15.9 ng mg-1 creatinine. The concentrations of urinary chlorophenols in previously exposed workers were of the same magnitude as those found in non-exposed controls and in the general population. The results show that it is unlikely that sawmill workers would be currently occupationally exposed to chlorophenols or polychlorinated dibenzo-p-dioxins and dibenzofurans via a contaminated work environment.