离子色谱法测定磷酸锂中微量的杂质元素

Determination of Potassium,Calcium and Magnesium Present as Impurities in Lithium Phosphate by Ion-Chromatography

对离子色谱法测定磷酸锂中钾、钙、镁杂质离子的方法进行研究.采用DX-80型离子色谱仪,分离柱为Ion Pac CS12A-5μm阳离子分离柱,用2×10^-2.mol·L^-1甲基磺酸溶液为淋洗液,流速为2 mL·min^-1,测定了磷酸锂中各钾、钙、镁杂质离子的含量,相关系数分别为0.999 6,0.999 3,0.999 4,相对标准偏差小于3%,样品回收率为98.1%～100.3%.

Ion-chromatography with depressed conductivity detection was applied to the determination of K, Ca and Mg present as impurities in lithium phosphate. The analysis was carried out on the DX-80 ion-chromatograph and the chromatographic column of Ion Pak CS12A-5 tan was used as cation separation column. 2×10^-2mol · L^-1 methylsulfonic acid solution was used as eluant at a flow-rate of 2 mL · min^-1, and K^＋ , Ca^2＋ and Mg^2＋ were determined in the eluate. Linear relationships between the peak areas and concentrations of K^＋ , Ca^2＋ and Mg^2＋ were obtained with correlation coefficients of 0. 999 6, 0. 999 3 and 0. 999 4 respectively, and detection limits of 0. 02 mg · L^-1 （for K＋ ） and 0. 05 mg · L^-1 （for Ca^2＋ and Mg^2＋ ） were found. Tests for precision and recovery were performed giving values of RSD＇s less than 3%, and values of recovery in the range of 98. 1%-100. 3%.