混合酸消解-电感耦合等离子体质谱法测定区域地球化学样品中的银  

Determination of Silver in Regional Geochemical Samples by Inductively Coupled Plasma-Mass Spectrometry with Mixed Acids Digestion

作　　者：潘倩妮 刘伟 何雨珊 阳国运 PAN Qianni;LIU Wei;HE Yushan;YANG Guoyun(Guangxi Zhuang Autonomous Region Geological and Mineral Testing Research Center,Naning 530023,China)

机构地区：[1]广西壮族自治区地质矿产测试研究中心,广西南宁530023

出　　处：《岩矿测试》2024年第3期459-467,共9页Rock and Mineral Analysis

基　　金：广西科技基地和人才专项“中-柬岩溶关键带科学与技术联合研究中心平台建设”(桂科AD20297091)。

摘　　要：建立了应用电感耦合等离子体质谱法(ICP-MS)分析地球化学样品中痕量银的方法,探究在动能歧视模式(KED)下,分别通入不同流速碰撞/反应气体(He)的干扰消除效果。Ag的两个稳定同位素因受到锆、铌氧化物(^(90)Zr^(16)O^(1)H、^(91)Zr^(16)O、^(92)Zr^(16)O^(1)H、^(93)Nb^(16)O)等的质谱干扰,对于干扰元素锆、铌含量较高而银含量低的样品,即使采用干扰系数校正也存在较大误差。结果表明:在KED模式下,通过加大氦气流速至7.0mL/min,基体元素如锆、铌氧化物产率降低,基本上消除了锆、铌氧化物对痕量Ag的多原子离子干扰。本文采用混合酸(硝酸-氢氟酸-高氯酸)敞开酸溶消解样品,残渣用王水复溶提取,结合KED模式选出干扰较小的同位素109Ag作为测定同位素,以103Rh作为内标校正基体干扰和仪器信号漂移。经国家一级标准物质验证,分析结果在标准值的允许误差范围内,方法的检出限(3SD)为0.005μg/g,测定结果的相对标准偏差(RSD,n=12)为1.43%~11.22%,满足地质矿产实验室测试质量管理规范(DZ/T 0130.4—2006)对精密度的要求。本方法适用于土壤、水系沉积物、岩石等区域地球化学样品中痕量银的分析。There exists much error during determination of trace silver in geochemical samples by traditional inductively coupled plasma-mass spectrometry(ICP-MS)due to the interference of zirconium(Zr)and niobium(Nb)oxides.To eliminate the disturbance,a simple and accurate method combining mixed acid digestion and ICPMS was built,in which the effect of He flow rate under kinetic energy discrimination(KED)mode was also investigated.Specifically,the samples were firstly digested by mixed nitric-hydrofluoric-perchloric acids.Then,the internal standard 103Rh was added into the test sample after nitrohydrochloric acid extraction to correct matrix interference and instrument signal drift.To further eliminate the interference of Zr and Nb oxides on Ag,the He flow of the collision pool was increased to 7.0mL/min,thus significantly reducing the mass spectrum interference of silver without deterioration of the signal-background ratio.Verified by national first grade reference materials,the analysis results were within the allowable range of the standard value.The detection limit(3SD)of the method was 0.005μg/g with the relative standard deviation of 1.43%−11.22%(n=12).This method is suitable for the analysis of silver in regional geochemical samples such as soil,stream sediments and rocks.

关 键 词：酸溶 电感耦合等离子体质谱法 区域地球化学样品 痕量银 KED模式 

分 类 号：O614.122[理学—无机化学] P595[理学—化学]