LC/MS/MS DETERMINATION OF PERFLUORINATED COMPOUNDS (PFCs) IN FILLETS OF MULTIPLE FISH SPECIES FROM THE CAPE FEAR RIVER BASIN, NORTH CAROLINA

摘要

Perfluorinated compounds (PFCs) are found in the environment as a result of their widespread use in industrial products. Human exposure to PFCs is of concern because some have shown toxicity in laboratory animals. One likely route of human exposure to PFCs is ingestion of fish. Previous reports in the literature have focused on measurements of PFCs in whole fish or fish livers; however, fish fillets are more commonly eaten. The current study measures levels of 3 perfluorinated sulfonates (PFBS, PFHS, PFOS) and the C6 - C12 perfluorinated acids in the fillets from eight fish species from two rivers in North Carolina that are in close geographical proximity but have been shown to have different PFC signatures. Fish were collected from the Haw and Deep Rivers in the Cape Fear River Basin by electroshocking. Fillet homogenates from individual fish were digested in 0.01N sodium hydroxide in methanol and diluted 10-fold with water. Solid phase extraction was performed on each sample using a Waters Oasis WAX cartridge. Calibration curves were prepared using similarly treated blank tilapia (Tilapia aurea) extracts for matrix correction. Quality control pools consisted of unspiked bluegill homogenate containing naturally occurring levels of PFCs. The analysis was performed by LC/MS/MS, using an Agilent 1100 and a Sciex API 3000 triple quadrupole mass spectrometer. Method precision, accuracy, recovery, and the limit of quantitation (LOQ) were determined. Measurements of PFCs were made in 8 fish species. Recovery was greater than 90percent for PFOS and greater than 75percent for all other PFCs. Interday and intra-day precision and accuracy measurements had RSD values of less than 20percent and were less than 20percent different from the theoretical values for all PFCs except C7. The LOQ ranged from 0.01 to 5.2 ng/g fish for all analytes. The method was applied to fillets collected from the following fish species: bluegill sunfish, redear sunfish, largemouth bass, channel catfish, carp, shad, bowfin, and redhorse sucker. Four analytes (PFOS, C10, C11, and C12) were detected above the LOQ in most fish and C9 was found above the LOQ in a few fish. Average PFOS concentrations were approximately two times higher in fish from the Haw River compared to the Deep River for all species except shad, bowfin, and channel catfish. Acid concentrations, on the other hand, were two to ten times higher in fish from the Haw River compared to fish from the Deep River for all species but carp and shad. The data indicate that the current analytical method is accurate, precise, and applicable to fillet samples from multiple fish species and that there are differences in PFC accumulation between species. The method will be useful in evaluating factors that influence PFC levels in fish and will help determine the importance of fish consumption for human exposures.