Evaluation of desulfuration methods for pyrethroid, organophosphate, and organochlorine pesticides in sediment with high sulfur content.

This study investigated different cleanup procedures to eliminate sulfur interference from sediments from a reclaimed mining site in Sparta, Illinois. Sonication extraction with activated copper powder was the most effective method to eliminate elemental sulfur. Extracts were then cleaned with a Florisil column before pyrethroid, organophosphate, and organochlorine pesticides were determined using gas chromatography with electron-capture detection. The method detection limits ranged from 0.03 to 0.68 microg/kg dry sediment. Recoveries for spiked samples were from 82.2% to 132.7% with relative standard deviations < 15%. Fifty-four sediment samples collected from 15 lakes and 1 stream in the proposed Illinois National Guard Armory were analyzed using the desulfuration procedure. Of the 26 target pesticides analyzed in sediment, 20 were detected above the detection threshold of 1 microg/kg. DDT was detected most frequently (found at 50% of the sampling sites), whereas permethrin was found at the greatest concentration.