Chlorinated organic compounds in aquatic biological resources of the Baltic region

The results of studying dependencies of levels of polychlorinated biphenyls (PCBs) and chlorinated pesticides in the liver and muscles of the main commercial fish species of the Baltic Sea (sprat, herring, cod, flounder), the Vistula and the Curonian Bay (pike-perch, bream, roach) on the fishing area, season and fish species have been considered. Determination of PCBs and pesticides has been carried out in accordance with MVI MN 2352-2005 "Method for simultaneous determination of residual amounts of PCBs and organochlorine pesticides in fish and fish products by gas-liquid chromatography". Separation, identification and quantification have been performed by the gas chromatography Varian 3400 on the DB-1701 column, 30 m ´ 0.25 mm ´ 0.25 mm, the column temperature 150-250 °C, the detector one - 300 °C. Identification and quantification have been performed by retention time of individual PCB congeners by the internal standard. The content of PCBs in liver of the Curonian and Vistula Bays fish is much lower than in liver of aquatic biological resources (ABR) of the Baltic Sea. Hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) are accumulated more intensively in liver of fish caught in the southern part of the Baltic Sea. β-HCH and γ-HCH prevail in the liver and muscle tissue of ABR samples as individual organochlorine pesticides (OCPs). The all three isomers of HCH are present in cod liver. Accumulation ratio in cod liver compared to that in the muscle tissue content reaches 7-8 units HCH for isomers, and for DDT and metabolites - 10-12 units. It has been proposed that the secondary admission of HCH in the aquatic environment and in ABG (delivery from sediments) takes place. Organochlorine pesticides such as hexachlorobenzene, heptachlor and aldrin are present in the Baltic Sea ABR in quantities below the detection limit used in the analysis methods. In spring and summer, there is an increased level of HCH and DDT in the liver of roach.