Comparison of different spectral resolution ICP-OES spectrometers for the determination of rare earth elements

This study investigates possible mutual spectral interferences of REEs for three commercially available spectrometers with different spectral resolutions. Comprehensive spectral interference data were obtained by using model solutions of REEs and spectral interference profiles of the most frequently used analytical lines are presented. The interference factors were calculated for line overlap correction and to confirm the effectiveness of the corrections, and model samples containing mixtures of rare earth elements were analyzed. This approach was useful only for spectrometers with low spectral resolution where the spectral interferences were found to be significant. As was expected, considerably better results were obtained by spectrometers with a high spectral resolution, as such corrections were unnecessary. The certified reference material REE-1 (the Strange Lake mine, Quebec, Canada) was used as a real sample representing REE-containing ore. Our results for both types of spectrometer confirm the assumption that high-spectral-resolution spectrometers provide better and more reliable results than low-spectral-resolution spectrometers with corrective factors. Nevertheless, the use of correction factors for the studied analytical lines does lead to improved results in many cases.