METHOD FOR DETERMINING LEAD (II) IN WATER AND BIOLOGICAL SAMPLES Russian patent published in 2019 - IPC G01N31/22 G01N33/20 G01N33/50 G01N21/78 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for determining lead (II) in aquatic environmental objects and biological samples. Method involves the preparation of a polymeric sensor film, which is placed in the test sample and the presence of lead (II) in it is determined by the color change of the polymeric sensor film, amount of which is determined by a calibrated color scale, previously obtained from at least 5 test samples with known lead concentrations. Polymer sensor film is placed in a test sample of the analyzed solution of known volume from 0.5 ml to 10 ml together with a mixture of magnesium acetate and acetic acid, taken in a ratio of 2.50⋅10^-3 mol/l : 1.25⋅10^-4 mol/l of the analyzed solution, and incubated for 2–18 minutes. Plasticized bis(ethylhexyl) ester of sebacic acid (DOS) poly(vinyl chloride) (PVC) film 2–7 mcm thick is taken as a polymeric sensor film, containing indicator neutral chromoionophore 9-dimethylamino-5-[4-(15-butyl-1,13-dioxo-2,14-ioxanoneadecyl)phenylimino]benzo[a]phenoxazine (ETH5418), 4-tert-butyl-calix[4]arene tetrakis(N,N-dimethylthioacetamide) ionophore (lead ionophore IV) and the ionic additive sodium tetrakis-[3,5-bis(trifluoromethyl)phenyl]borate (NaTFPB) in the ratio: 16.7 mg of PVC, 33.3 mcl DOS, 10 mmol/kg DOS ETH5418, 11 mmol/kg DOS NaTFPB, 60 mmol/kg DOS lead ionophore IV, placed on the carrier. Determining the presence of lead (II) in the test sample is carried out by visual-test method by comparing the color of the polymer sensor film with a calibrated color scale.

EFFECT: proposed method is simple, express and sensitive.

1 cl, 5 dwg, 2 tbl, 4 ex