METHOD OF DETERMINING 2,4-DICHLOROPHENOXY ACETIC ACID IN BIOLOGICAL MATERIAL Russian patent published in 2012 - IPC G01N33/50 

FIELD: chemistry.

SUBSTANCE: biological material containing 2,4-dichlorophenoxy acetic acid is infused twice for 30 minutes while stirring with ethyl acetate portions, the mass of each of which is twice higher than the mass of the biological object. Separate extractions are separated from solid particles of the biological material and merged. The solvent is evaporated. The residue is repeatedly treated with acetone. The acetone extractions are separated and merged. The acetone is evaporated in an air current at temperature 18-22°C to dry residue. The residue is dissolved in chloroform, extracted with a buffer solution at pH 10-11. The extract is separated, acidified with 24% hydrochloric acid to pH 2-3 and saturated with sodium chloride. Extraction is carried out with acetyl acetate. The ethyl acetate extraction is separated, dehydrated and evaporated at 18-22°C in an air current until complete removal of the solvent. The residue is dissolved in a mixture of hexane-diethyl ether solvents in volume ratio 6:4, chromatographed in a column with silica gel using a hexane-diethyl ether mobile phase with volume ratio 6:4. Eluate fractions containing the analysed substance are merged. The eluent is evaporated in an air current at temperature 18-22°C. The residue is dissolved in a mixture of acetonitrile-0.025 M potassium dihydrophosphate solution solvents in volume ratio 1:1 and chromatographed via HPLC using reversed-phase sorbent Symmetry C-18 sorbent, mobile phase acetonitrile - 0.025 M potassium dihydrophosphate solution in volume ratio 1:1 and a photodiode matrix based detector.

EFFECT: invention increases accuracy of determination.

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