Spectrophotometric Determination of Beryllium with Chrome Azurol S -Application to Waters

Abstract

A simple, rapid and direct spectrophotometric method for the determination of beryllium II is described. The method is based on the reaction beryllium II with chrome azurol S in the presence of cetylpyridinium chloride at pH 5.0 forming a stable blue coloured complex which has an intense absorption at 620 nm. Beer's law was obeyed over the range of 0.25-100 µg/25 ml. The molar absorptivity and Sandal's sensitivity of the coloured complex are 1.02×10 4 l.mol-1 .cm-1 and 0.00883 µg.cm-2 , respectively. The interference caused by a number of common cations and anions can be removed by using EDTA as a masking agent. The method has been applied successfully to the determination of beryllium II in different water samples.