Abstract: The residues of organochlorine pesticides(OCPs)and polychlorinated biphenyls (PCBs) in 20 different yogurtspecimens of 16 brands from China(Beijing, Tianjin, Shanghai, Guangzhou, Shijiazhuang), Spain and France were determined byGas Chromatography-Electron Capture Detector (GC-ECD). The sources of the characteristic residues of HCHs, DDTs andPCBs in yogurt were explained. The results indicated that all the yogurt samples contained the residues of HCHs and DDTs, whichwere still the main contributors to OCPs in yogurt samples. The β-HCH and p,p-DDE were the characteristic residues isomerof HCHs and DDTs in yogurt, respectively. Furthermore, the main contributors of ∑PCBs were the sum of the 5CBs and6CBs, and the PCB202. Also, the 4,4- and 2,3,5- substitution patterns were the characteristic residues of PCBs in yogurt.

Key words: gas chromatography-electron capture detector (GC-ECD), yogurt, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs)