微波消解–电感耦合等离子体质谱法测定钛白粉中8种杂质元素

Determination of Eight Impurity Elements in Titanium Dioxide by Microwave Digestion and Inductively Coupled Plasma Mass Spectrometry

摘要: 钛白粉应用领域的扩展使其杂质元素的要求越来越严苛。目前分析方法，受检出限、光谱干扰等限制，仅能检测部分微量元素，且检出限远不能满足现今工业的更高需求。试验建立了一种通过微波消解进行前处理并通过电感耦合等离子体原子发射质谱法(ICP-MS)测定钛白粉中Tl、Al、In、Cu、Mo、V、Ba、Se八个元素含量的分析方法，且考察了基体对这八个杂质元素的干扰情况。样品以HNO₃、HF微波消解，标准溶液加入二氧化钛基体消除干扰，ICP-MS同时测定多元素。该方法检出限在1.6 µg/kg~42 µg/kg之间，定量限在5.2 µg/kg~140.8 µg/kg之间；相对标准偏差(n = 7)在1.83%~4.05%之间，测试结果稳定可靠；标准加入法测得加标回收率稳定在96%~110%之间。方法简便快捷，适用于高纯度钛白粉原料的质量控制和检测。

Abstract: The continuous expansion of the application fields of titanium dioxide has led to increasingly strict requirements for its impurity elements. Currently, the analytical methods are limited by factors such as detection limits and spectral interference, and can only detect some trace elements. Moreover, the detection limits are far from meeting the higher quality demands of the titanium dioxide industry today. An analytical method was established for the pre-treatment by microwave digestion and the determination of the content of eight elements including Tl, Al, In, Cu, Mo, V, Ba, and Se in titanium dioxide by inductively coupled plasma atomic emission mass spectrometry (ICP-MS). The interference of the matrix on the impurity elements was also investigated. The samples were digested by microwave with HNO₃ and HF, and the standard solution was added to a titanium dioxide matrix to eliminate interference, then, multiple elements were simultaneously determined by ICP-MS. The detection limit of this method is between 1.6 µg/kg and 42 µg/kg, and the quantification limit is between 5.2 µg/kg and 140.8 µg/kg; the relative standard deviation (n = 7) is between 1.83% and 4.05%, and the test results are stable and reliable. The standard addition method showed that the recovery rate remained stable between 96% and 110%. The method is simple and fast, and is suitable for quality control and inspection of high-purity titanium dioxide raw materials.