SCREENING-PROCEDURE FOR ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDE-RESIDUES IN EGGS USING A SOLID-PHASE EXTRACTION CLEANUP AND GAS-CHROMATOGRAPHIC DETECTION

A solid-phase extraction (SPE) screening procedure for the isolation a nd gas chromatographic (GC) determination of organochlorine and organo phosphorus pesticide residues in eggs is described. Eggs are extracted with acetonitrile. The extract is subjected to a cleanup on tandem C1 8 and Florisil SPE columns. Organochlorine and organophosphorus pestic ide residues are determined by GC with electron capture and flame phot ometric detection, respectively. Because the injected extracts are fre e from matrix interferences, the amount of residue present is easy to calculate. The average recoveries of 9 spiked organochlorine pesticide residues (0.01-1.0 ppm) ranged from 80.9 to 91.1%. The average recove ries of 7 spiked organophosphorus pesticide residues (0.02-0.50 ppm) r anged from 80.3 to 89.5%. The SPE method results in a 90% reduction in organic solvent consumption and an 85% reduction in hazardous waste p roduction compared with the AOAC methodology.