DETERMINATION OF MERCURY AT THE PICOGRAM PER MILLILITER LEVEL USING IMMOBILIZED HORSERADISH-PEROXIDASE

New test method and test device for the mercury (II) determination at the pg/mL level were developed based on the mercury inhibitory on hors eradish peroxidase immobilized on solid supports - in the cells of the polystyrene plate and on the chromatographic paper. The reactions of o-dianisidine, 3,3',5,5'-tetramethylbenzidine and o-phenylenediamine o xidation by hydrogen peroxide were used as the indicator reactions. Th e mercury inhibitory effect increased in tile presence of thiourea. Un der the elucidated optimal conditions the calibration curves for the m ercury determination showed a linear relationship between the peroxida se inhibition degree and the mercury concentration in tile range of 0. 1-1000 pg/mL. The mercury detection limits were 0.1-10 pg/mL independe nce on the concrete indicator reaction. The analysis completed in 15 m in. The proposed test device was applied to the mercury determination in underground waters of Moscow region. The mercury content obtained w as coincident with that obtained by atomic-fluorescent method with col d vapour.