全自动石墨消解-电感耦合等离子体质谱法测定岩石样品中稀土元素

本文建立了以全自动石墨消解仪消解样品，“加酸-消解-赶酸-定容-摇匀”全程用软件控制，以Rh、Re为内标，电感耦合等离子体质谱法测定岩石中La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y 15种稀土元素含量的方法。通过对岩石国家一级标准物质GBW07103、GBW07104、GBW07105、GBW07108、GBW07109、GBW07110、GBW07112、GBW07122进行方法酸用量、方法精密度、准确度和检出限的测试研究。结果表明：按照消解程序消解的上述岩石国家标准物质，各元素测定值与标准值一致，相对标准偏差在0.98%～4.41%之间，方法精密度优于常用的电热板消解法，方法精密度、准确度和检出限满足地质矿产实验测试质量管理规范的要求，该方法用酸量较少，自动化程度高，可应用于批量样品的测试。

Determination of Rare Earth Elements in Rock by Inductively Coupled Plasma Mass Spectrometry with Automatic Graphite Digestion

A new automatic graphite digestion method was developed to measure 15 rare earth elements in rock samples with inductively coupled plasma mass spectrometry, including La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y. The whole process consists of acid injection, sample digestion, acid removal, precise dilution and mixture, which is controlled by software thoroughly with Rh and Re as internal standards. The effects of acid dosage, as well as the precision, accuracy and detection limit of the method have been studied with national rock standard materials GBW07103, GBW07104, GBW07105, GBW07108, GBW07109, GBW07110, GBW07112, GBW07122. The results show that, when the rock samples have been digested according to the digestion procedure, the measured values were consistent with the certified values, and the RSD of components in samples ranged from 0.98% to 4.41%. The precision of the method is better than that of the traditional electric plate digestion method. The precision, accuracy and detection limit of the method meet the requirements of the specification of testing quality management for geological laboratories. This method requires less acid dosage and provides a high degree of automation, therefore can be applied to batch sample testing.