Dimitrova, RT; Stoykova, II; Yankovska-Stefanova, TT; Yaneva, SA; Stoyanchev, TT
Aiming to meet the European requirements for monitoring of pesticide residues in food of animal origin, the analytical scope of the methods in Bulgaria need to be extended. Herein, we introduce a new method that performs better analytical characteristics and allows more compounds to be determined, compared to the existing method used for determination of organochlorine pesticides in meat. So far, in the national monitoring program a total of eight organochlorine pesticides have been analyzed: aldrin, heptachlorepoxide-trans isomer, HCH - alpha, beta, gamma isomers, p,p'-DDE, p,p'-DDD and p,p'-DDT, by means of a method based on EN 1528:2001-Fatty food - determination of pesticides and polychlorinated biphenyls (PCBs). Using our new method, it is possible seven additional pesticides to be determined: dieldrin, endosulfan- alpha and beta isomers, endosulfan sulfate, HCB, heptachlor, heptachlorepoxide-cis isomer. The method is based on accelerated solvent extraction technique, liquid - liquid partitioning with acetonitrile-n-hexane, clean-up step on a home-made silica gel column and GC-ECD determination of pesticides. The validation is performed according to the recommendations in the document SANTE/11945/2015 and it meets the acceptability criteria. The proposed method was successfully used in laboratory proficiency test where OCPs included were HCH isomers - beta (Z-score of rezult: 0.1), p,p'- DDE (Z-score of rezult: -0.6), Endosulfansulfate (Z-score of rezult: 0.5).