Liquid-Liquid Extraction and Higher Order Derivative Spectrophotometric Determination of Cobalt with 1,10-Phenanthroline and Rose BENGAL

Abstract

Higher order derivative techniques are mainly used in deconvoluting the overlapping absorption spectra of various analytes in their determination. The procedure utilizing higher order derivatives in molecular absorption spectrophotometry essentially are based on the formation of binary complex viz. metal reacting with a chromogenic reagent. This paper reports a fourth order derivative spectrophotometric procedure for the determination of traces of cobalt based on the liquid-liquid extraction of ternary ion - asociation complex -cobalt, 1, 10-phenanthroline, rose bengal into chloroform. The developed procedure is simple, rapid, reliable and allows the determination of as low as 6 ppb of cobalt in high purity rare earth oxides and salts.