Complexometric determination of mercury(II) by use of 4-amino-5-mercapto-3-propyl-1,2,4-triazole as replacing reagent

Abstract

A simple, rapid, and selective complexometric method is proposed for the determination of mercury(II). Mercury(II) is first complexed with excess of EDTA and the surplus EDTA is back-titrated (pH 5-6) with zinc sulphate solution, with Xylenol Orange as indicator. 4-Amino-5-mercapto-3-propyl-1,2,4-triazole is then added to displace EDTA from the Hg-EDTA complex and the released EDTA is titrated with zinc sulphate solution. Reproducible and accurate results are obtained in the range 1-40 mg of mercury, with a relative error of approximately 0.4%. 1982.