Determination of organochlorine pesticides and polychlorinated biphenyls in chicken eggs by matrix solid phase dispersion

A multiresidue method for the determination of 20 organochlorine pesticides (aldrin, endrin, dieldrin, α-BHC, β-BHC, γ-BHC, δ-BHC, α-chlordane, γ-chlordane, 4,4'-DDE, 4,4'-DDT, 4,4'-DDD, endosulfan I, endosulfan II, endosulfan sulfate, endrin aldehyde, heptachlor, heptachlor epoxide, endrin ketone and methoxychlor) and eight PCB congeners (PCB 20, 28, 52, 101, 118, 138, 153, 180) in chicken eggs has been developed and validated. The samples were extracted by a simple and fast matrix solid-phase dispersion (MSPD) method using Florisil as the sorbent material and dichloromethane/hexane (1:1) as the eluting system. Further purification of the extracts was conducted using a conventional clean-up procedure with concentrated sulphuric acid. Determination and quantitation of PCBs and OCs residues was carried out using a gas chromatograph equipped with an electron capture detector (GC-ECD). A mass spectrometric detector (GC-MS) in the selected ion monitoring (SIM) mode was used for confirmation purposes. The method detection limits were <0.7 ng g-1 for all PCBs and OCs and the relative standard deviations for analyses of samples fortified over the range of 10-200 ng g-1 were <8%. All compounds provided average recoveries (spiked at five concentration levels) ranging from 82% to 110%. The proposed method was used to analyze 30 commercial products taken from local markets in the course of a 3-month sampling campaign