Collect. Czech. Chem. Commun. 1991, 56, 206-215

Polarographic determination of alkaline earths with azo dyes

L. S. Kopanskaya, V. T. Meryan and V. A. Smelov

Laboratory of Electrochemical Methods, Institute of Chemistry, Moldavian Academy of Sciences, 277028 Kishinev, U.S.S.R.


Magnesium and calcium can be determined in an alkaline medium as complexes with azo dyes by square-wave polarography on the dropping mercury electrode or by linear sweep voltammetry on the hanging mercury drop. The linear dependence of current on magnesium concentration in the presence of IREA magnezone is valid within half an order; in the presence of calcone in a wider range. The lower limit of determination is 2.10-7 mol 1-1. The dependence of current on calcium concentration in the presence of calcion is linear within the interval of 5.10-7 to 4.10-6 mol 1-1 in the voltammetric determination with accumulation.