采用电感耦合等离子质谱技术,研究了高岭土中微量组分Fe₂O₃,TiO₂,K2O, Na2O,CaO,MgO及Pb,Cr,Mn,As,Cd,Cu等杂质元素含量的质谱分析方法。样品经HNO3-HF低温溶解至清亮后,Si以四氟化硅的形式从溶液中挥发,消除了Si基体的干扰,继续加热至干,(1+3)HNO3浸取。在线加入内标元素45Sc,115In,204Tl,采用内标法进行校正,有效克服了基体效应、接口效应及仪器波动所产生的影响,通过优化仪器工作参数,选择适当的待测元素的同位素,有效地克服了因质谱干扰所带来的影响。讨论了分析样品的制备过程中温度对砷元素测定的影响。该方法的加标回收率是95.0%-101.0%,相对标准偏差(RSD)是1.1%-2.01%。 对高岭土标准物质(编号GBW03122)进行了测定,测定结果与标准值相吻合。该方法具有快速、简便、准确等特点,可用于高岭土及陶瓷产品中微量成分及杂质元素的含量分析。

The direct determination method of trace composition,Fe₂O₃,TiO₂,MnO,K2O,Na2O,CaO and MgO,and impurity elements, Pb,Cr,Cd,Cu and As,in kaolin was studied by using inductive coupled plasma mass spectrometry(ICP-MS).After the samples were dissolved completely in HF-HNO3 at low temperature,silicon was volatilized in the form of SiF4 and separated from the solution.Then the solution was continually evaporated to dry to get the solid substance which was dissolved by the nitric acid (1+3).The internal elements 45Sc,115In and 205Tl were added on line and the effect of matrix,interface and fluctuation of instrument was overcome effectively by using internal standard calibration method.By choosing the optional operating parameters and appropriate isotopes of element to be detected,the influence of mass spectrometry interference was conquered effectively.The effect of temperature in samples preparation on the determination of arsenic was tested.The recovery for spiking sample is in the range from 95.0% to 101.0% and the relative standard deviation is in the range from 1.1% to 2.01%.In order to check the accuracy of the method,the kaolin standard reference material GBW03122 was also analyzed,and the analytical values conformed to standard values.This method has the characteristics of being simple,rapid and accurate,and can be used in the testing of trace composition and impurity elements in kaolin and ceramic product.