[The quantitative determination of sulfhydryl and imidazole groups in proteins by the method of inversiochronopotentiometric titration].

A method is suggested for a quantitative determination of sulphydryl and imidazole groups in proteins. The method is based on the capacity of Zn2+ and Co2+ to bind selectivity with sulphur and nitrogen atoms in bioligands. The mentioned reactions are fixed by one of most sensitive methods of the electrochemical analysis, the inversiochronopotentiometric titration. The method was tested with the solutions of amino acids and proteins. The sensitivity of the method is 10(-8)M, a relative error is +/- 1.5%.