氟化铵快速分解-电感耦合等离子体质谱法测定地球化学样品中的稀土元素  

Determination of Rare Earth Elements in Geochemical Samples by Inductively Coupled Plasma Mass Spectrometry(ICP-MS) with Ammonium Fluoride Rapid Decomposition

作　　者：郭振华[1] 王木荣 王艳超[1] GUO Zhenhua;WANG Murong;WANG Yanchao(Experimental Application Research Center,Institute of Geology,Sinochem General Administration of Geology and Mining,Zhuozhou,Hebei 072750,China)

机构地区：[1]中化地质矿山总局地质研究院实验应用研究中心,河北涿州072750

出　　处：《中国无机分析化学》2023年第4期363-367,共5页Chinese Journal of Inorganic Analytical Chemistry

基　　金：中国地质调查局项目(DD20190816)。

摘　　要：测定地球化学样品中的微量稀土元素常用混酸分解法或碱熔融法,这些常规方法往往存在耗费试剂量多、基体效应大、操作周期长等缺点。采用氟化铵作熔剂,在旋盖聚四氟乙烯坩埚中220℃熔融样品后,采用2 mL硝酸和0.5 mL高氯酸+硫酸(1+1)在电热板上继续分解,建立了氟化铵分解-电感耦合等离子体质谱法测定岩石、土壤和水系沉积物中15种微量稀土元素的分析方法。方法能快速、有效地分解样品,经三种国家标准物质验证(岩石、土壤、水系沉积物),方法的准确度Δlgc在0.001~0.02,测定值与认定值相符。方法检出限为0.001~0.04μg/g,精密度RSD在1.1%~4.9%,能够满足微量稀土元素的分析要求,方法简单快捷、消耗试剂少、检出限低、精密度与准确度好等特点,适合于地球化学等地质样品微量稀土元素的批量快速分析测定。Determination of trace rare earth elements in geochemical samples is usually carried out by mixed acid decomposition method or alkali melting method.These conventional methods often have disadvantages such as large amount of reagents, large matrix effect, and long operation period.A new method for the determination of 15 trace rare earth elements in rock, soil and stream sediments by inductively coupled plasma mass spectrometry(ICP-MS) was established by using ammonium fluoride as flux to melt the samples in a capped polytetrafluoroethylene crucible at 220 ℃ and then using 2 mL nitric acid and 0.5 mL perchloric acid+sulfuric acid(1+1) to decompose on an electric heating plate.This method can decompose the samples quickly and effectively.After verification by three national standard materials(rock, soil, water system sediment),the accuracy of the method, Δlgc,is between 0.001 and 0.02,and the measured value is consistent with the certified value.The detection limit of the method is between 0.001 and 0.04 μg/g, and the precision RSD is between 1.1% and 4.9%,which can meet the analysis requirements of trace rare earth elements.With the characteristics of simple and fast, with less reagent consumption, low detection limit, good precision and accuracy, it is suitable for the batch rapid analysis and determination of trace rare earth elements in geochemical and other geological samples.

关 键 词：地球化学样品 稀土元素 氟化铵 旋盖聚四氟乙烯坩埚 电感耦合等离子体质谱法 

分 类 号：O657.63[理学—分析化学] TH843[理学—化学]