Determination of Polychlorinated Biphenyls in Aquatic Organisms as Pollution Bioindicators at Ultratrace Concentration Levels

Abstract

A procedure for the determination of indicator congeners of polychlorinated biphenyls (PCBs) in the aquatic organisms of Lake Baikal, an aquatic ecosystem characterized by trace levels of pollutants in water, has been validated. The procedure included ultrasonic extraction of analytes from samples weighing up to 0.5 g and purification of the extracts with sulfuric acid. Gas chromatography–mass spectrometric analysis with detection of analytical peaks in the multiple reaction monitoring mode and the use of ¹³C-labeled surrogate internal standards ensured the determination in a range of 0.10 to 15 ng/g with an accuracy of ±δ = 24–28% (P = 0.95) and, for congener no. 180, in a range of 0.010 to 15 ng/g with an accuracy of ±δ = 45%. The composition and accumulation level of PCBs, including indicator and dioxin-like congeners, were determined in the Baikal fish species Coregonus migratorius (Georgi, 1775), Comephorus baicalensis (Pallas, 1776), and Comephorus dybowskii (Korotneff, 1904) and in the mollusks Benedictia baiсalensis (Gerstfeldt, 1859) and Radix auricularia (Linnaeus, 1758). The studied aquatic organisms were evaluated as sensitive indicators of ultratrace amounts of PCBs in the water of Lake Baikal.