Simultaneous kinetic spectrophotometric determination of Sn(II) and Co(II) by the calculation of the variation of ratio kinetic profiles

Abstract

A simple kinetic spectrophotometric method has been developed for the simultaneous determina tion of cobalt(II) and tin(II) without any preliminary separation based on the different rates of their oxidation reaction with Fe(III) and 1,10 phenantroline in micellar medium. The reduced product of the reaction, Fe(II), forms a color complex with 1,10 phenanthroline and makes a visible spectrophotometric signal for indirect monitoring of Sn(II) and Co(II) concentrations. This method is based on the calculation of the vari ation of ratio kinetic profiles. At first, the ratio kinetic profile is obtained by dividing the kinetic profile of the sample by that of an interferent and then the signal at the first time of ratio kinetic profile is subtracted from the signals at all times to obtain the variation of ratio kinetic profiles. The proposed method is suitable for the analysis of binary mixtures with completely overlapping absorption spectra that shows a difference in their rate constants in a given reaction. The proposed method was successfully employed for the analysis of various water samples and canned products (pineapple juice).