METHODOLOGICAL FEATURES OF THE DETERMINATION OF MERCURY IN FISH SAMPLES (USING FISH FROM THE KUREISKOE RESERVOIR AS AN EXAMPLE)

Methodological features of the determination of mercury in fish sample s by the Surma-Aho method were examined. The method is simple, efficie nt, convenient in operation, and economical; it can be used in field c onditions. The results of determining mercury in fresh and sun-dried f ish samples in terms of wet mass are in good agreement, and the analys is results obtained for sun-dried samples in different laboratories ar e characterized by adequate reproducibility. It was found that the pre datory fish species (pike and perch) inhabiting the area of the Kureis koe Reservoir accumulate mercury in concentrations higher than the max imum permissible values (0.5 mg/kg). The concentrations of toxic methy lated mercury varied in the range from 33 to 96% of the total mercury content, depending on the total concentrations and fish species.