摘要
应用电感耦合等离子体质谱法(ICP-MS)分析土壤中的镉元素时,锆的氢氧化物、钼的氧化物、锡的同位素会对镉造成严重的干扰,导致准确测定土壤中镉的难度较大。本文采用电感耦合等离子体串接质谱法(ICP-MS/MS),选取无同质异位素干扰的^(111)Cd为分析谱线,在MS/MS模式下碰撞反应池中通入的氧气可以与^(94)Zr^(16)O^(1)H^(+)、^(95)Mo^(16)O^(+)进行电子转移、去氢、加氧等反应,抑制这些多原子离子对^(111)Cd的重叠干扰。结果表明:氧气流量越大,去除多原子离子的效果越好,当氧气流量在0.45mL/min时,溶液中2000μg/L以下的锆、1000μg/L以下的钼在^(111)Cd处形成的多原子重叠干扰小于0.005μg/L。实验在石墨消解仪中采用氢氟酸-硝酸-高氯酸消解样品,盐酸复溶,溶液定容稀释至1000倍测定,方法检出限(3δ)达到0.003μg/g;本方法经过国家土壤一级标准物质验证,11个国家土壤一级标准物质的测量值和认定值的相对误差在±7%以内,3个国家土壤一级标准物质的精密度(RSD,n=12)小于5%。本方法可以作为土壤样品中痕量镉元素的分析方法。
BACKGROUND:When using inductively coupled plasma-mass spectrometry(ICP-MS)to analyze soil,the zirconium hydroxide,molybdenum oxide,and tin isotopes can cause serious interference on cadmium,which makes it difficult to accurately determine cadmium in soil samples.OBJECTIVES:To develop a method for accurate determination of Cd in soil samples.METHODS:ICP-MS/MS was used,and ^(111)Cd without isobaric interference was selected as the analysis line.In MS/MS mode,the oxygen introduced into the collision reaction cell can be reacted with 111 Zr^(16)O^(1)H^(+),^(111)Mo^(16)O^(+),inducing electron transfer,dehydrogenation,oxygenation and other reactions to inhibit the overlapping interference of these polyatomic ions on ^(111)Cd.RESULTS:Oxygen flow was the key factor in this method.0.45mL/min oxygen flow can reduce oxide interference to less than 0.005μg/L when zirconium concentration was lower than 2000μg/L and molybdenum concentration was below 1000μg/L.The method has been verified by the national reference materials.The relative error of the measured value and recognized value of the 11 national reference materials was within±7%,and the relative standard deviation(n=12)of three soil reference materials was less than 5%.CONCLUSIONS:Triple quadrupole ICP-MS oxygen reaction mode can eliminate Zr and Mo polyatomic ion interference on Cd,and this method can be used for the determination of trace Cd in soil samples.
作者
赵志飞
任小荣
李策
郭朝
宋娟娥
龚华
ZHAO Zhi-fei;REN Xiao-rong;LI Ce;GUO Zhao;SONG Juan-e;GONG Hua(Agilent Technologies(China)Co.,LTD,Beijing 100102,China;Hubei Geological Research Laboratory,Wuhan 430022,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210000,China)
出处
《岩矿测试》
CSCD
北大核心
2021年第1期95-102,共8页
Rock and Mineral Analysis
关键词
土壤
镉
氧气反应模式
多原子离子
电感耦合等离子体串接质谱法
soil
cadmium
oxygen reaction mode
polyatomic ion
triple quadrupole inductively coupled plasma-mass spectrometry
