The determination of some impurities in high purity beryllium by differential cathode-ray polarography

Abstract

Methods are described for the determination of copper, lead, cadmium, zinc, nickel, cobalt, iron and manganese in high purity beryllium by differential cathode-ray polarography. Impurities are separated by solvent extraction of diethyldithiocarbamates from buffered beryllium chloride solutions at pH 4·5 to 5·0, and elements determined in suitable supporting electrolytes. A technique has been developed for the separation of zinc and cobalt in 0·5 M pyridine-M potassium chloride by subtractive polarography by using reverse potential sweep. The methods give limits of detection of 0·2 p.p.m. for each element with a single 500-mg beryllium sample and have been applied to electrolytically refined metal.