[Determination of organochlorine pesticides and polychlorinated biphenyl congeners residues in eggs by gas chromatography with electron capture detection (GC-ECD)].

A procedure of clean-up with H2SO4 after extraction with a shaking machine using n-hexane, and fast determination of some organochlorine residues in eggs by GC-ECD with PCB2 and PCB209 as internal standards was established. The test results showed that with this method satisfactory recoveries(84.31%-116.77%), relative standard deviation (6%-18%) and detection limits (0.07 ng/g-0.35 ng/g) could be obtained. In comparing with the Soxhlet method, this method is simpler in pre-treatment, lower in cost and less in sample amount. It can determine organochlorine pesticides and some PCBs in the same extract, simultaneously with enough accuracy, sensitivity and permissible RSD. It is a suitable procedure for determining micro-amounts of organochlorine pollutants in foods. The results showed that p, p'-DDE was detected in maximum; p, p'-DDT next; and PCBs very little, that were usually less than 10 ng/g in the eggs from some Chinese markets. It was found that most of PCBs in eggs were the congeners with 3-5 chlorine atoms.