PROCESS OF VOLTAMPEROMETRIC DETERMINATION OF CONCENTRATION OF PERMANGANATE IONS IN ZINC SULFATE SOLUTION Russian patent published in 2002 - IPC

FIELD: analytical chemistry, automatic and proximity analysis of technological solutions of zinc winning as well as sewage or circulating water at non-ferrous metallurgy plants. SUBSTANCE: process is based on voltamperometric determination manganese (VII) in chloride-ammonia medium in presence of demethylglyoxym and EDTAA. Demethylglyoxym transfers manganese (VII) to electrochemically active complex which selectively reduces on mercury electrode in presence of surplus concentrations of Mn(VII) and Zn(II). Injection of EDTAA into analyzed solution makes it possible to suppress interfering effect of ions Ni(II), Co(II) and Fe(II) in process of polarographic determination of permanganate ions. Measurements are conducted against background 2M NH₄Cl + 2M NH₄OH = 2•10^-3 M demethylglyoxym +2•10^-3MEDTAA by method of differential pulse polarography. Volt-ampere curve is registered in voltage range from -0.8 to -1.2 V at rate of potential scanning 10.0 mV/s. Content of Mn(VII) is determined by height of cathode peak with potential -0,98B∓0,01B. EFFECT: raised selectivity, accuracy and timeliness of process. 12 dwg