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National Water Quality Laboratory

Saturday March 17, 2018

USGS Open-File Report 95-140

Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory — Determination of Organochlonine Pesticides and Polychlorinated Biphenyls in Bottom Sediment by Dual Capillary-Column Gas Chromatography with Electron-Capture Detection

William T. Foreman, Brooke F. Connor, Edward T. Furlong, Deborah G. Vaught, and Leslie Merten


A method for the determination of 30 individual organochlorine pesticides, total toxaphene, and total polychlorinated biphenyls (PCBs) in aquatic bottom sediment is described and laboratory performance data are provided. The method was developed in support of the U.S. Geological Survey’s National Water-Quality Assessment program and is based on conventional Soxhlet extraction using dichloromethane. Two aliquots of the sample extract are quantitatively injected onto a styrene-divinylbenzene gel permeation column and eluted with dichloromethane. This gel permeation chromatography step removes inorganic sulfur and large naturally occurring molecules from the sediment extract. The first aliquot is analyzed for semivolatile organic compounds by gas chromatography with mass spectrometric detection. The second aliquot is further split into two fractions by combined alumina/silica adsorption chromatography prior to the determination of the organochlorine pesticides and PCBs by dual capillary-column gas chromatography with electron-capture detection (GC/ECD). This report completely describes and is limited to the determination of the organochlorine pesticides and PCBs by GC/ECD. Current (February 1995) data-reporting limits have been set at 1 to 5 micrograms per kilogram for 30 chlorinated pesticides, 50 micrograms per kilogram for total PCBs and 200 micrograms per kilogram for toxaphene.

VIEW the report. (pdf)

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