U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting, Colorado Springs, Colorado, September 20-24, 1993, Water-Resources Investigations Report 94-4015

Isolation of Lipophilic Organic Contaminants Along the Upper Mississippi River Using A Semipermeable Membrane Device

Abstract

The detection of many environmental contaminants in water is often hindered by their transient nature and low concentration. However, these compounds can represent a significant environmental hazard to biota and humans through bioconcentration. Traditional methods of analyzing aquatic biota are complicated by variations in species, sex, age, reproductive stage, location, behavioral patterns, metabolism, and water conditions. A new sampling device consisting of a tubular semipermeable membrane of low-density polyethylene filled with synthetic fish fat, triolien, which mimics the mechanism of bioconcentration, may resolve some of these problems. To evaluate the effectiveness of these sampling devices, they were deployed at nine sites along the upper Mississippi River; caged fish at three of these sites were used for comparison purposes. The devices and caged fish were collected over an eight-week period, and indigenous fish were collected at the end of the study. Compounds were extracted from the triolien by back dialysis into an appropriate solvent. Fish tissues were ground and extracted wet into a solvent and the lipid removed. All samples were analyzed by gas chromatography/mass spectrometry (GC/MS). Target compounds were pesticides, herbicides, and polychlorinated biphenyls (PCBs). Comparisons of compound concentrations in the fish samples and sampling devices will be used to determine the effectiveness of this technique as a monitoring tool for bioconcentration.