Development of spectrophotometric determination of beryllium in beryl minerals using chrome Azurol S

AbstractA developed, direct, rapid, and sensitive spectrophotometric determination of beryllium in beryl minerals with Chrome Azurol S (CAS) as a chromogenic reagent was developed in the present article. The determination was performed without either solvent extraction or ion exchange separation of beryllium from its matrix. The stable 1:1 Be-CAS complex was formed instantly with duration time of at least 24h with constant absorbance. Different parameters such as wavelengths, pH, EDTA concentration and dye concentration were studied for the optimum determination of beryllium. Interference due to presence of high aluminum concentrations was overcome by adding 5% EDTA disodium salt solution. Maximum absorbance for Be-CAS complex was performed at λmax 568NM using acetate buffer at pH 4.6. Beer’s law was obeyed in the range from 0.02 to 9ppm with molar absorptivity ε=0.22×104mol−1cm−1 and an average standard deviation of 0.7. The R.S.D for 10 replicate measurements of 1ppm Be was 1.2%