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 and gas chromatographic (GC) determination of organochlorine and organophosphorus pesticide residues in eggs is described. Eggs are extracted with acetonitrile. The extract is subjected to a cleanup on tandem C18 and Florisil SPE columns. Organochlorine and organophosphorus pesticide residues are determined by GC with electron capture and flame photometric detection, respectively. Because the injected extracts are free 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 recoveries of 7 spiked organophosphorus pesticide residues (0.02-0.50 ppm) ranged 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 production compared with the AOAC methodology.