Occurrence of some chlorinated enol lactones and cyclopentene-1,3-diones in chlorine-treated waters

Article abstract of DOI:10.1021/es00007a022

Enol lactones (5-dichloromethylene-2-furanones) and 2,2- dichlorocyclopentene-1,3-diones, a total of six compounds, were synthesized and subsequently qualitatively and quantitatively determined in a sample of chlorination stage liquor from the bleaching of softwood kraft pulp (CBL), in chlorine-treated natural humic water (HW), and in three samples of drinking water treated with various disinfectants (DW1-3). All the compounds could be observed in the samples, in concentrations ranging from 2 to 170 μg/L in CBL, from 7 to 65 ng/L in HW, and at most a few nanograms per liter in DW1- 3. The compounds were found to be weakly mutagenic in the Ames assay (strain TA100 without metabolic activation). The contribution of the compounds to the total mutagenicity in the studied samples was negligible. The compounds were unstable in aqueous solutions at pH 7.0, and under these conditions they were in part converted to 5-(dichloromethyl)-5-hydroxy-2-furanones. In acidified methanol, the enol lactones were partially converted to 5-(dichloromethyl)- 5-methoxy-2-furanones.