Determination of phosphorus in zirconium-niobium alloy by ion association spectrometry

An ion association spectrophotometric method has been developed for the determination of phosphorus in zirconium-niobium alloy. The sample was dissolved in HF-HNO3 mixture and excess fluoride was complexed with boric acid. The analyte in the solution was oxidized with potassium permanganate and was extracted as phospho molybdo complex into n-butyl acetate. The organic phase was equilibrated with acidified crystal violet to form colored ion associates. The organic phase was taken in acetone and absorbance was measured at 582 nm. No interference was found in the presence of large quantity of zirconium, niobium and silica. The LOD was found to be 0.055 μg g-1 (3σ). ROD is 0.4-2.3 % and molar absorptivity is 2.7x105 1 mole-1 cm-1. (author)