微波消解-电感耦合等离子体质谱法测定高岭土中10种微量元素

高岭土作为重要的铝硅酸盐,其微量元素的含量决定着高岭土产品的性能指标.高岭土的三种国家标准物质成分GBW03121、GBW03122、GBW03122a中均未含有As、Sb等10种微量元素的标准值,在高岭土的检测中只能采用近似的岩石标准物质作为监控物质,对高岭土组分的准确分析有一定影响.本文通过微波消解技术,对比了硝酸...

Determination of 10 Trace Elements in Kaolin by ICP-MS with Microwave Digestion

BACKGROUND: As an important aluminosilicate, trace element contents affect the performance of the product. The kaolin standard substances GBW03121, GBW03122, GBW03122a lack the recommended values of ten elements such as arsenic and antimony. Similar rock standard materials were used for monitoring the determination procedure, but the accurate results of the kaolin samples may be affected.OBJECTIVES: To establish a method for accurate determination of 10 trace elements in kaolin sample such as arsenic and antimony.METHODS: With microwave digestion technology, the nitrate-hydrofluoric acid system and nitrate-hydrofluoric-peroxide system were compared for the procedural heating conditions and dissolution time of microwave digestion. Interference factors of the inductively coupled plasma mass spectrum were also investigated.RESULTS: The detection limits of 10 elements were 0.01-0.09mg/kg, and measurement limits were 0.03-0.30mg/kg. The accuracy and precision of the method were directly verified by using rock reference materials. The element recovery was between 90.9% and 103.2%, and the relative standard deviation (RSD) was between 1.2% and 5.8%. At the same time, a comprehensive evaluation of the uncertainty of the method was carried out, and the method was proved to be accurate and reliable.CONCLUSIONS: This method has little acid dosage, shortens the measurement time, and reduces the damage on the environment and human, making it suitable for the batch analysis of 10 trace elements in kaolin samples. The method also provides a reference for the determination of the certified values of 10 trace elements such as As and Sb in the national standard material of kaolin.