Kinetic-catalytic determination of cobalt by oxidation of Pyrogallol Red by hydrogen peroxide

Abstract

A kinetic-spectrophotometric method for the determination of trace amounts of cobalt(II) based on its catalytic effect on the hydrogen peroxide oxidation of Pyrogallol Red (PGR) is proposed. Under optimum conditions, cobalt can be determined in the range 0.20–13.00 ng ml^–1. The limit of detection is 0.16 ng ml^–1 of Co and the limit of quantitation is 0.54 ng ml^–1 of Co. The precision and accuracy of the method using a fixed time of 5 min were also determined. The influence of 18 foreign species is discussed.