Extractive Spectrophotometric Determination of Cobalt with Benzyltriethylammonium Chloride

Department of Chemistry, Gauhatt University, Gauhati-781 014 Manuscript received 1 July 1985, revised 29 April 1987, accepted 5 June 1987 A simple and rapid extractive spectrophotometric method for the determination of cobalt(II) is described The ion-association formed between the SCN--complex of CoII and benzyltriethylammonium ion is extracted into 1,2-dichloroethane in a wide range of pH. The extracted species has an absorption maximum at 625 nm, and obeys Beer's law for 0.5 - 55 µg ml-1 of CoII; the molar absorptivity being 0.179 x 104 dm3 mo1-1. cm-1. Optimum conditions for colour development and interference from foreign ions have been studied