Gel permeation and florisil chromatographic cleanup and gas chromatographic determination of organochlorine pesticides in eggs.

Cleanup of residual organochlorine pesticides (OCPs; alpha-, beta-, gamma-, and delta-BHC; aldrin; dieldrin; p, p'-DDE; o,p'-DDT; p,p'-DDD; and p,p'-DDT) in eggs by gel permeation chromatography (GPC) and Florisil minicolumn chromatography is described. Ten OCPs in purified extract are determined by gas chromatography with electron capture detection. The lipids extracted from whole egg are cleaned up first by GPC with an Envirogel column and an ethyl acetate-cychlohexane (1 + 1, v/v) mobile phase and then by Florisil minicolumn chromatography with 15% (v/v) diethyl ether-hexane eluant. Cleanup is highly efficient. Average recoveries of 10 spiked OCPs (0.0025-0.0125 ppm) ranged from 81 to 101%, with coefficients of variation between 1 and 14%. The detection limit was 0.001 ppm for the 10 OCPs.