Occurrence of chlorinated paraffins in beluga whales (Delphinapterus leucas) from the St. Lawrence River and rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio) from Lake Ontario

Samples of 25 dead beluga whales (Delphinapterus leucas) from the St. Lawre nce River estuary, as well as samples of 10 rainbow trout (Oncorhynchus myk iss) and 3 carp (Cyprinus carpio) caught in western Lake Ontario were analy zed for total short- (C-10-C-13) and medium-(C14C17) chain chlorinated para ffins (SMCCPs) using gas chromatography-low resolution negative chemical io nization mass spectrometry (GC-NCI-MS) in the selected ion monitoring mode (SIM). Short- and medium-chain chlorinated paraffins were quantitatively id entified using two commercial preparations. SMCCPs were detected in all sam ples. Results ranged from 1.1 to 59 mu g/g wet weight in beluga liver tissu e, from 6.4 to 166 mu g/g wet weight in beluga blubber, and from 0.41 to 9. 7 mu g/g wet weight in the two freshwater species. The beluga results are h igher than those reported for marine mammals in Europe. Total short- and me dium-chain chlorinated paraffin levels in the beluga blubber are comparable to previous Sigma CPCB and Sigma DDT results for the same population of be luga whales. The mean Sigma SMCCP concentration in the carp was 0.90 mu g/g wet weight and 2.7 mu g/g wet weight in the rainbow trout. Results from th e freshwater species are comparable to those reported for fish sampled from other industrially impacted waterways in North America but are elevated re lative to marine species from European studies. Comparison of the SIM GC-NC I-MS data with results of gas chromatography-high resolution negative ion m ass spectrometry (GC-HR-NIMS) analysis from another study showed that the t wo analytical techniques are not congruent The differences may be due to th e effects of coeluting interfering organochlorine substances.