石英砂ICP-OES测试溶样方法对比研究:酸溶法和碱熔法

Research on comparing the sample digestion methods for ICP-OES testing quartz sand:acid sissolution and alkali fusion

石英砂的ICP-OES测试制样方法分为酸溶法和碱熔法。酸溶法消解缺乏统一的流程,实验中常存在消解不完全、微量元素测定不准确的问题;碱熔融法操作繁琐,容易引入杂质。探明此两种制样方法对石英砂ICP-OES测试结果的影响很有意义。分析对比了酸溶法和碱熔法对石英砂中Al、Zr、Mg等杂质元素检测结果的影响,由能谱分析可知,酸溶法中不溶颗粒相主要成分是F、Al、Zr、Si和Mg杂质元素。实验结果表明,酸溶法制样会造成石英砂中Al、Zr和Mg杂质含量低于实际值,实验偏差大。碱熔法制样测得Al、Zr、Mg杂质含量明显高于酸溶法,经加标回收实验可知,碱熔法实验的回收率介于93.6%~116.3%之间,符合检测要求,但碱熔法存在检测限高、相对偏差较大的缺点。

Acid dissolution and alkali fusion are two methods for preparing quartz ICP-OES testing samples. The method of acid digestion process for preparing ICP-OES samples is not standardized which is not completely digested and inaccurate, The method of alkali fusion operate tediously and the sample is easy to be polluted. Therefore, it makes sense to find out the impact on testing of two methods. In this paper, two methods including acid wet digestion and alkali-fusion method were used and compared in testing Al, Zr, Mg impurity element contents of quartz sand. By Scanning Electron Spectrometer （SEM/EDX）, the undissolved particles are composed of F, Al, Zr, Si and Mg. These results suggest that acid digestion process has some loss of Al, Zr and Mg content, causing lower value of the testing results and experimental bias. The results of ICP-OES show that Al, Zr, Mg content by alkali fusion digestion method is higher than that by acid digestion. The results of recovery experiment show that the method had better accuracy, and the recovery rates are in the range of 93.6%116.3%, which meets detection requirements. But it＇s detection limit and RSD is higher.