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STABLE CHLORINE ISOTOPE ANALYSIS OF CHLORINATED ORGANIC CONTAMINANTS
Citation:
Reddy, C. M., T. I. Eglington, L. J. Heraty, B. D. Holt, N. C. Sturchio, J L. Lake, AND K. A. Maruya. STABLE CHLORINE ISOTOPE ANALYSIS OF CHLORINATED ORGANIC CONTAMINANTS. Presented at Society of Environmental Toxicology and Chemistry Annual Meeting, Philadelphia PA, November 11-18, 1999.
Description:
The biogeochemical cycling of chlorinated organic contaminants in the environment is often difficult to understand because of the complex distributions of these compounds and variability of sources. To address these issues from an isotopic perspective, we have measured the, 37Cl (37Cl/35Cl in ? relative to standard mean ocean chloride), in commercial mixtures of Aroclors (1016, 1242,1254,1260, and 1268), ppDDT, chlordane, toxaphene, and polychlorinated biphenyls (PCBs) extracted from sediments. The sediments were from New Bedford Harbor (NER), contaminated with Aroclors 1242, 1254, and 1016, and the Turtle River Estuary (TRE), contaminated primarily by Aroclor 1268. The 37Cl of the commercial mixtures ranged from -5.10 to 1.22 ?. Two different toxaphenes had the most depleted 37Cl values of -5.10 ? and -4.21 ?. The ppDDT had a value of -3.49 ?, and the Aroclors exhibited a narrow range of isotopic composition from -3.37 to -2.11 ?. There was no correlation between the percent chlorine by mass in the Aroclors and their 37Cl. Chlordane was the most enriched with a 37Cl of 1.22 ?. For theNBH sediments, the 37Cl of the total PCBs ranged from -4.54 to -2.53 ? and some were clearly depleted in 37Cl relative to the Aroclor 1242, 1254, and 1016 mixtures that were analyzed (-3.38 to -2.11 ?). The 37Cl of the total PCBs extracted from the TRE (-2.84 to -2.25 ?) were more similar, but slightly enriched, when compared to the 37Cl of three different lots of Aroclor 1268 (-3.22 to -2.44 ?). These differences may be from several environmental processes, which we will discuss.