DETERMINATION OF CE, PR, ND AND SM IN HIGH-PURITY LA2O3 BY INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

High purity lanthanum oxide was analysed to determine traces of Ce, Pr, Nd, and Sm by employing inductively coupled plasma atomic emission spectrometry (ICP-AES). Lanthanum oxide was dissolved in nitric acid and the solution was nebulized into the plasma generated by a RF generator (56 MHz; 1.5 kW). Analytical lines of Ce, Pr, Nd, and Sm, which were free of interference from the spectral lines of both La and the other rare earths, were scanned on a Jobin-Yvon, Model JY-38 THR-1000 1m-Czerny-Turner monochromator. Standards containing the four analytes (Ce, Pr, Nd, and Sm) in the concentration range 0.01-0.2-mu-g/ml and La at 2 mg/ml were used for calibration. Detection limits ranged between 6 and 16 ng/ml for the four analytes in aqueous solution.