离子色谱法测定杂多酸中的酸根离子

Determination of acid radical ions in heteropoly acid by ion chromatography

建立了离子色谱法测定杂多酸中酸根离子的含量。杂多酸样品用20%KOH溶液前处理,用70 mmol/L KOH洗脱液淋洗,Dionex IonPac AS16阴离子交换色谱柱分离,抑制型电导检测器检测。杂多酸中常见的钨酸根、钼酸根和磷酸根离子检出限在0.8×10^(-6)~5.6×10^(-6),杂多酸样品的酸根离子在0.025、0.050、0.100 g/L加标水平的回收率在97.2%~101.6%,该方法的相对标准偏差在0.60%~1.19%。结果表明,该方法前处理简单、灵敏度高、准确度高、重复性好,适用于杂多酸中酸根离子含量的测定。

An ion chromatography method is established for the determination of acid radical ions in heteropoly acid.The samples are pretreated with 20% KOH solution,eluted with 70 m M KOH eluent,separated by Dionex Ion Pac AS16 anion exchange column,and detected by suppressed conductivity detector. It is shown that the detection limits of tungstate,molybdate and phosphate ions in heteropoly acid are between 0. 8 ppm and 5. 6 ppm,the recoveries of acid radical ions at 0. 025,0. 050 and 0. 100 g·L^(-1) are in the range of 97. 2%-101. 6%,and the relative standard deviations are between 0. 60% and 1. 19%.The results show that the method is simple,sensitive,accurate and reproducible,which is suitable for the determination of acid radical ions in heteropoly acid.