Determination of light rare earth elements in hydroxide concentrates of apatite and bastnaesite by ICP-OES method

The method was developed of determining La, Ce, Pr, Nd, Sm, Eu, Gd, and Y in hydroxide concentrates of apatite and bastnaesite within the concentration range of detection threshold via units to tens of per cent. The determination was performed by optical emission spectrometry with an inductively coupled plasma source (OES-ICP) following conversion of the sample into a solution. Spectral interferences of the rare earth elements were studied, suitable analytical lines were selected and the Gauss-Jordan elimination method of the equation system solution was used for spectral effects corrections. The effects were investigated of salts and acids on the magnitude of the analyte signal detected in the analytical zone of the ICP discharge. The signal magnitude observed was found to depend on the concentration of salts and acids. It was equal for all elements under study. Measurement sensitivity was better than 1% and determination specificity was tested by a comparison with results obtained by atomic absorption spectrometry, X-ray spectral analysis and photometry. (author). 8 tabs., 27 refs