A KINETIC-DUAL STANDARD ADDITIONS METHOD FOR SIMULTANEOUS DETERMINATION OF INTERFERING BINARY-MIXTURES COMPENSATED BY A SYNERGISTIC COEFFICIENT - SIMULTANEOUS DETERMINATION OF MOLYBDATE AND TUNGSTATE

A kinetic-dual standard additions method for simultaneous determinatio n of interfering binary mixtures is proposed, and the principles discu ssed. The deviations of the absorbance from additivity in kinetic syst ems, caused by a synergistic effect between the two catalysts, are eff ectively compensated with the defined synergistic catalytic coefficien t. The hydrogen peroxide-iodide kinetic reaction catalyzed by molybdat e and tungstate was studied with a stopped flow injection technique, a nd the conditions for simultaneous determination of molybdate and tung state were established. Contents of molybdenum and tungsten in differe nt samples were determined with proposed procedure, the recoveries wer e 97.6-102.1% and 96.9-98.6%, and the relative standard deviations wer e 2.3-3.4% and 1.6-2.6% respectively.