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

A simple, rapid and direct spectrophotometric method for the determination of beryllium II is developed. 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 g/25 ml. The molar absorptivity and Sandal's sensitivity of the coloured complex are 1.02104 l.mol-1.cm-1 and 0.00883 g.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.