EVALUATION OF LIPID-CONTAINING SEMIPERMEABLE-MEMBRANE DEVICES FOR MONITORING ORGANOCHLORINE CONTAMINANTS IN THE UPPER MISSISSIPPI RIVER

Organochlorine contaminants sequestered in lipid-containing semipermea ble membrane devices (SPMDs) were compared to those found in tangentia l-flow ultrafilter permeates as part of a pilot study at 10 sites in t he Upper Mississippi River system. Caged and feral fish from three pri mary sites were also analyzed for comparison. Concentrated organochlor ine (OC) compounds were readily extracted from the SPMDs by dialysis i nto hexane, and samples were analyzed by gas chromatography-negative c hemical ionization-mass spectrometry. Fish and water samples were proc essed by conventional methods. Reasonable agreement was found between analyte SPMD-derived water concentrations and measured values of ultra filter permeates; however, concentrations of the same analytes in cage d fish did not appear to be proportional to water concentrations deriv ed from SPMDs and ultrafilter permeates. The greatest number of OC com pounds was detected in SPMDs; fewer were detected in caged fish and fe ral fish.