电感耦合等离子体质谱法测定钒钛磁铁矿中的稀土元素

Determination of rare earth elements in vanadium-titanium magnetite by ICP-MS

准确、快速地测定钒钛磁铁矿中的稀土元素,对钒钛磁铁矿的高效利用有着重要的作用。针对目前国内外缺乏钒钛磁铁矿中稀土元素分析方法的问题,试验选取不同矿区具有代表性的5件钒钛磁铁矿作为试验样品,采用盐酸、氢氟酸、硝酸外加硫酸混合酸溶分解的方式,并结合电感耦合等离子体质谱仪检出限低、灵敏度高、干扰小的特点,对钒钛磁铁矿中稀土元素测定过程中的仪器条件、测定模式、内标元素、同位素选择及质谱干扰进行研究。结果表明,在最佳的仪器工作参数的条件下,采用STD模式,选择干扰小且丰度大的同位素,选择合适的内标元素Rh和Re,能够有效地降低基体效应引起的信号强度漂移。此外,通过精密度试验及加标回收试验发现,采用电感耦合等离子体质谱法测定钒钛磁铁矿中的稀土元素能获得良好的精密度与准确度,此方法准确有效。

Accurate and rapid determination of rare earth elements in vanadium titanium magnetite plays an important role in the efficient utilization of vanadium titanium magnetite.In view of the lack of analysis methods for rare earth elements in vanadium titanium magnetite at home and abroad,5 representative vanadium titanium magnetite crystals from different mining areas were selected as test samples,and hydrofluoric acid,nitric acid and sulfuric acid mixed acid solution decomposition method were adopted.Combined with the characteristics of inductively coupled plasma mass spectrometer with low detection limit,high sensitivity and low interference,the instrument conditions,internal standard elements,isotope selection and mass spectrum interference during the determination of rare earth elements in vanadium titanium magnetite were studied.The results show that the signal intensity drift caused by matrix effect can be effectively reduced by using STD mode,selecting the isotopes with small interference and large abundance,and selecting the appropriate internal standard elements Rh and Re under the conditions of the optimal instrument parameters.In addition,it is found by the precision tests and standard recovery tests that the inductively coupled plasma mass spectrometry method can obtain good precision and accuracy for the determination of rare earth elements in vanadium titanium magnetite.