Determination of 10 impurity elements in 5N high-purity cesium nitrate by inductively coupled plasma tandem mass spectrometry

A direct ICP-MS/MS method was established for analyzing 10 impurities in 5 N-grade CsNO 3 . • Simple sample preparation with effective elimination of Cs-matrix interference. • Exhibits superior analytical performance (high sensitivity, low LODs, wide range) for high-purity material analysis. Cesium nitrate (CsNO 3 ) crystals occupy a strategic position in high-tech applications owing to their unique physicochemical properties. Therefore, establishing an accurate and efficient multi-element impurity analysis method is of great practical significance. In the analysis and detection of high-purity substances, high-concentration matrices often cause signal interference to trace impurities, while matrix separation is prone to introduce new impurities, thereby affecting the accuracy of detection results. In this work, inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was employed for the quantification of impurity elements, and a novel dynamic reaction mode with multi-gas settings (no gas/he/NH 3 ) was innovatively adopted. A method for the determination of 10 interference-prone impurity elements in 5 N high-purity cesium nitrate was established by optimizing the flow rate of collision gases to mitigate the matrix effect of cesium nitrate and selecting an appropriate internal standard for matrix effect correction. The experimental results indicated that Li and pb were analyzed under the no gas mode; Si was determined via mass shift at an NH 3 flow rate of 0.75 mL/min; ca was determined via mass shift at an NH 3 flow rate of 3.00 mL/min; K was determined via mass shift at an NH 3 flow rate of 1.25 mL/min; Rb was determined via mass shift at an NH 3 flow rate of 1.75 mL/min; Mg, Na, and Al were determined via mass shift at a he flow rate of 3.0 mL/min; and Fe was determined via mass shift at a he flow rate of 4.8 mL/min. The limits of detection of the method ranged from 0.01 to 0.07 ng/mL, and the relative standard deviations were between 0.75% and 10.14%. Spiked recovery experiments on real samples yielded a recovery range of 94.9%–110.9%, which verified the reliability of the proposed method. Through an in-depth study on the determination of impurities in 5 N high-purity cesium nitrate, this work established an accurate and comprehensive ICP-MS/MS method for the detection of impurities in high-purity cesium nitrate, which provides a valuable reference for the determination of impurities in other high-purity rubidium and cesium salts. Download: Download high-res image (118KB) Download: Download full-size image