KINETIC DUAL STANDARD ADDITIONS METHOD FOR THE DETERMINATION OF 2 MUTUALLY INTERFERING ANALYTES - MOLYBDATE AND TUNGSTATE

A kinetic dual standard additions method for determination of two mutu ally interfering analytes is proposed. The deviations of absorbance fr om additivity in kinetic systems, caused by synergistic effects of cat alysts, are compensated with the defined synergistic catalytic coeffic ient. The hydrogen peroxide-iodide kinetic reaction catalysed by molyb date and tungstate was studied with the stopped-flow injection techniq ue and the conditions for simultaneous determination of Mo and W estab lished. The molybdenum and tungsten contents in different samples were determined with recoveries of 97.6 similar to 102.1% and 96.9 similar to 98.6%, and relative standard deviations of 2.3 similar to 3.4% and 1.6 similar to 2.6%, respectively.