A multi-residue procedure was devised for the extraction, cleanup and determination of forty seven pesticides in fortified soil samples. Most of the compounds were determined by gas chromatography interfaced with either the electron capture or the flame photometric detector. Several nitrogen containing pesticides were quantitated using a fluorescence detector in conjunction with a high performance liquid chromatographic system. Various methods of extraction were compared for several pesticides. A silica gel column, eluted sequentially with various solvents, was used for cleanup and separation of compounds into groups. Several different derivatization procedures were used to render some pesticides more amenable to gas chromatographic detection. A dynamic fluorogenic labelling detector was designed and characterized for the high pressure liquid chromatographic analysis of six N-methylcarbamate and two carbamoyl oxime pesticides. Lannate, Matacil, Temik, Baygon, carbofuran, Sevin and Mesurol could be extracted from sandy soil at the 0.01 ppm level with recoveries ranging from 83 to 115%. Somewhat lower recoveries were experienced from sandy loam and siltry loam soils. Zectran could not be reproducibly chromatographed under the liquid chromatographic conditions chosen for the separation. No cleanup was required prior to the liquid chromatography of the soil extracts; no significant interferences were observed for the unclean extracts.

"Contract no. 68-02-1706."

I. Determining multiclass pesticide residues in soil by gas chromatography. -- II. Dynamic fluorogenic labelling detector for carbamates."