Gas chromatographic/mass spectrometric identification of chlorinated and oxygenated cyclohexene artifacts formed during the analysis of chlorinated water samples.

Chlorinated and oxygenated cyclohexene derivatives detected in methylene chloride extracts of chlorinated drinking water were demonstrated to be artifacts produced during sample preparation. Commercial methylene chloride contains cyclohexene as a preservative, and this reacted during the extraction/concentration process to produce microgram amounts of chlorocyclohexene, 2-chlorocyclohexanol, trans-1,2-dichlorocyclohexane, cyclohexenone and cyclohexenol. Quantitative analysis indicated that over 90% of the initial cyclohexene was consumed during the process. Dechlorination of drinking water with sodium arsenite significantly reduced but did not eliminate cyclohexene artifact formation.