This document specifies a gas chromatographic method with electron capture detection (ECD) for the determination of organochlorine pesticides (OCPs) in compound feeds and oil and fats.
The method is applicable to animal compound feed, oils and fats and fish meals with a water content up to about 20 % by weight and oil/fatty samples containing residues of one or more of the following OCPs, toxaphene and some of their isomers and degradation products:
— dichlorodiphenyltrichloroethane (DDT) (the isomers op'-DDT, pp'-DDT, pp'-TDE (pp'-DDD), and pp'-DDE);
— endosulfan (as the sum of α-/β-isomers);
— hexachlorobenzene (HCB);
— hexachlorocyclohexane isomers α-HCH (α-BHC), β-HCH (β-BHC), γ-HCH (γ-BHC or lindane);
For the following OCPs, the method is considered a screening method. Additional in-house validation is required for reporting validated data.
— chlordane (as the sum of chlordane isomers and oxychlordane);
— heptachlor (as the sum of heptachlor and heptachlor epoxide);
— and trans-nonachlor.
A limit of quantification (LOQ) for the mentioned OCPs of 5 µg/kg is intended to be obtained. However, 10 µg/kg applies for heptachlor, aldrin, endrin, dieldrin, and endosulfan (α-/β– and sulphate). Individual laboratories are responsible for ensuring that the equipment that they use, achieves these limits of quantifications. The LOQs apply to the individual OCPs.