Optimized spectrophotometric determination of trace cobalt and manganese by their catalysis of the tiron—hydrogen peroxide reaction

✍ Scribed by M. Otto; J. Rentsch; G. Werner

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 623 KB
• Volume: 147
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(83)80092-0

✦ Synopsis

A kinetic-spectrophotometric method for the determination of traces of cobalt(H) and manganese(I1) based on their catalytic effect on the tiron-hydrogen peroxide indicator reaction is proposed. Optimal conditions for determination of Co(I1) are deduced from response surface studies, considering the sensitivity and the blank absorbance as responses. The detection limit is 0.05 ng Co ml'. The Mn(II)-catalyzed reaction was optimized for l,lO-phenanthroline as the activator by the simplex method and for 2,2'bipyridine as the activator by response surface methodology on the basis of a previously described mechanistic model of the catalytic reaction. In the presence of 2,2'-bipyridine, the detection limit is 0.2 ng Mn ml-'. The influence of foreign metal ions on both determinations is discussed and is related in the case of the 2,2'-bipyridine-activated Mn(II)catalyzed reaction with model generated effects of these metal ions.