Toxaphene analysis in the Great Lakes fish samples and fate modeling

Toxaphene was one of the most heavily used insecticides in the United States until most uses were banned in 1982. It is a complex mixture of chlorinated bornane and chlorinated bornenes. Toxaphene is now considered as one of the most worrisome organochlorinated pollutants because of its bioaccumulation and long-term persistence. The concentrations of toxaphene in the fish samples, especially in the Great Lakes fish samples, have raised concerns. The EPA has established the Great Lakes Fish Monitoring Program (GLFMP) in order to monitor these contaminant variation trends. Toxaphene as one of persistent organic pollutants was analyzed in top predator fish in the Great Lakes region. In this project, both whole fish and fish fillet collected from the Great Lakes in 2004 and 2005 were analyzed for total toxaphene and some selected Parlars. Sample preparation, cleanup procedures and GC/MS analysis procedures will be discussed. Electron ionization (EI) tandem ion trap mass spectrometry (MS/MS) is the method that was used to measure toxaphene concentrations in fish tissue samples. Accurate quantification was obtained by selection of parent ion m/z 125 and daughter ion m/z 89. This approach eliminates interferences from other polychlorinated pollutants commonly present in fish samples. The Electron Capture Negative Ion (ECNI) method is an alternative and sensitive method that has been used for measuring toxaphene in environmental samples. This method was also assessed for toxaphene analysis in fish samples. The results for both methods were consistent and correlated well. The CoZMo-POP2 model combined with a food chain model were used to estimate the toxaphene concentration in the top predator fish in the Great Lakes. The modeling procedure and results will be presented. Monte Carlo based multi-media fate model was also used in this study to evaluate the effect of different toxaphene emission rates to the concentration of toxaphene in top predator fish in the Great Lakes. The modeled results will also be discussed.