摘要
准确测定岩石、土壤或矿物等地质样品中的关键金属元素含量,是开展关键金属矿产基础理论研究、探讨关键金属元素超常富集成矿机制、开展找矿勘查和绿色利用的重要前提。由于激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)在整体元素分析方面具有高灵敏度、多原子离子干扰少、样品消耗少和前处理简单等优势,被认为是一种具有较大潜力的绿色地质分析技术。然而,天然地质样品的组成十分复杂多样,在使用LA-ICP-MS进行元素整体分析之前通常需要将其消解均一化,这些前处理流程不仅复杂、费时费力,并且需要使用大量浓酸,增加了样品丢失和污染的风险。本文提出了将氟化铵消解方法作为LA-ICP-MS整体元素分析前处理技术,利用氟化铵具有高沸点,能在常压条件下对难溶矿物进行化学分解的特点,可实现岩石中不同类型矿物的物理结构均质化和化学成分均匀化,形成超细粉末颗粒。氟化铵消解后的粉末可以直接进行粉末压片,通过加入In内标结合岩石参考物质外标校正,实现LA-ICP-MS快速多元素整体定量分析。通过重量法可以准确获得Si元素质量分数。通过对5个国际岩石标准物质的分析测试,整体分析测试精度优于5%,45个主微量元素(包括关键金属元素)分析准确度优于10%,表明了本方法的有效性和可靠性。本方法仅需要2h即可完成样品完全消解,可批量操作。相比于传统酸消解流程,新方法大幅降低无机酸的用量,具有绿色环保的特点。
BACKGROUND:The accurate determination of concentrations of key metal elements in geological samples(such as rocks,soils or ores)is an important foundation for the basic theory research of critical metal ores,supernormal enrichment mechanism of critical metal elements,mineral resource exploration and green utilization of mineral resources.Laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)has advantages of providing adequate sensitivity,low interferences of polyatomic ions,small quantities of sample consumption and simple sample preparation.It is perceived as a green geological analytical technique with great potential in the whole elemental determination.However,the pretreatment of geological samples is the key factor limiting its pervasive application.The current bulk analysis of LA-ICP-MS is limited by the problem of sample homogenization.Most of the traditional pretreatment techniques are obtained by physical grinding,which has low efficiency and the risk of cross contamination.Therefore,new pre-processing techniques for geological samples need to be proposed to meet the requirements of LA-ICP-MS analysis.OBJECTIVES:To develop a new pre-treatment technology for geological samples and establish a rapid,efficient,green,and environment-friendly LA-ICP-MS elemental quantitative analysis technology.METHODS:The ammonium fluoride(NH4F)was used to digest five rock reference materials(BCR-2,BHVO-2,AGV-2,RGM-2,GSP-2).Ultrafine particulate powders obtained after evaporation and stirrer processes were directly pressed into tablets.The rapid whole elemental quantitative analysis of LA-ICP-MS can be achieved by adding the indium(In)internal standard and external standard correction of geological rock reference material.The digestion time of NH4F,the morphology,element composition,element distribution and other characteristics were also investigated.The mass fraction of SiO2 was evaluated to the total normalization 100%and gravimetric method.RESULTS:The results show that 2h digestion time can completely de
作者
陈达辉
曾显丽
谢筠奕
胡兆初
刘勇胜
罗涛
何焘
张文
CHEN Dahui;ZENG Xianli;XIE Junyi;HU Zhaochu;LIU Yongsheng;LUO Tao;HE Tao;ZHANG Wen(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Wuhan),Wuhan 430074,China)
出处
《岩矿测试》
CAS
CSCD
北大核心
2023年第5期1020-1030,共11页
Rock and Mineral Analysis
基金
国家重点研发计划项目(2021YFC2903000)课题“战略性矿产微区原位分析技术及应用”。
