Determination of trace amounts of praseodymium by third-derivative molecular absorption spectrophotometry

Abstract

A third-derivative molecular absorption spectrophotometric procedure is described for the determination of trace amounts of praseodymium (Pr). The procedure is based on the reaction of praseodymium with Bromopyrogallol Red (BPR) in acetate-buffered medium. The influence of various instrumental parameters and reaction conditions on the colour development of the BPR-Pr complex has been investigated. The proposed method is free of interference from up to 100-fold amounts of other rare earth elements (except yttrium, lanthanum and neodymium). In conjunction with ion-exchange separation, the proposed method has been applied to the determination of praseodymium in aluminium metal samples.