Determination of Rubidium and Cesium in Low Grade Lithium Mica by Microwave Digestion-Inductively Coupled Plasma Mass Spectrometry

A method for the determination of rubidium and cesium in low grade lithium mica by microwave digestion-inductively coupled plasma mass spectrometry was established. The optimal sample processing conditions were determined through experiments. Rhodium was used as the internal standard to correct the matrix interference, and the detection limits (3s) of rubidium and cesium were 0.032 μg·L^-1 and 0.018 μg·L^-1, respectively, with the linear correlation coefficients greater than 0.999 7. The substantial samples were tested for 11 times, and the standard recovery experiment was conducted. The RSDs (n=11) were in the range of 2.3%-4.6%, and the recovery were in the range of 96.5%-105%. After the national standard product verification, the determination value of this method was consistent with the standard value. The method was fast and accurate, can meet the requirements of rubidium and cesium analysis in low grade lithium mica.