Rare earth elements (REEs) is a peculiar group of chemical elements. Their determination in geological samples is important and complex due to their low concentrations and problems with spectral and non-spectral interferences. Herein, the operating conditions of an inductively coupled plasma optical emission spectrometer were optimized for the determination of REEs using experimental designs. The signal-to-background ratio (SBR) of the REEs emission signals and the Mg II/Mg I line intensity ratio were evaluated as response functions. According to the results obtained, three different sets of operating conditions were selected and classified as robust, semi‑robust and best SBR conditions. Limits of detection (LOD), SBR and relative standard deviation of the blank solution (RSDblank) were determined. The semi-robust condition (RF power of 1250 W and nebulizer gas flow rate of 0.90 L min-1) exhibited lower LOD and RSDblank than others tested operating conditions.
rare earth elements; ICP OES; optimization; SBR; Mg II/Mg I
