Estimation of selected phenols in drinking water with in situ acetylation and study on the DNA damaging properties of polychlorinated phenols.

Gas chromatography/mass spectrometry with selected-ion monitoring (GC/MS-SIM) method were used to analyze 23 selected phenols in natural and drinking waters by an in situ acetylation technique. This method was suitable for determining phenol concentrations at the ng/L level because of less background interference and better recoveries. The application range for all these phenols was from 0.01 or 0.04 to 10 micrograms/L, using a 800 ml water sample. The levels of trace phenols in four Taiwan water treatment plants were in the range of 12-312 ng/L. The polychlorinated phenols, namely 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol, were evaluated for their ability to induce deoxyribonucleic acid (DNA) damage using a DNA precipitation assay employing mouse embryonic fibroblast cells (C3H10T1/2) with or without a liver microsomal activation system. These agents exhibited a weak positive response when microsomal activation enzymes were present in this assay. When the tetrachlorohydroquinone, a toxic metabolite of pentachlorophenol, was measured by the same method without the activation system, a significant and dose-dependent DNA damage was found. This result indicates that in the evaluation of the carcinogenic potential of these agents, their corresponding metabolites should be taken into consideration. DNA strand breakage caused by these active metabolites may play an important role in the tumorigenetic process of polychlorinated phenols.