摘要
采用ICP-MS测定红壤中的Fe、Co、Ni、Cu、Pb、Zn、Ga、Ge、Cd 9个元素时,氩等离子炬中的基体元素Ar、N、O形成多原子离子,会对Fe的测定产生强烈的质谱干扰。云南地区红壤中Fe质量分数往往超过10%,因此在分析中尽量降低Fe的背景信号及分析信号强度的同时还要保证Cd、Ge、Ga等微量元素的分析灵敏度。研究了利用动能歧视(KED)碰撞技术测定这些元素的最佳工作条件,为避免样品分解中Ge的挥发损失,采用HNO 3-HF-H 2 O 2分解试样,Rh和Ir作内标元素消除非质谱干扰,用校正公式消除质谱干扰。标准物质分析及实际测试表明,KED模式能显著降低Fe的背景干扰并能消除Fe对Ge的氧化物干扰,Co/ClO比值为10.6时Fe能得到最佳信背比,其他微量元素亦能保证良好的分析灵敏度及准确度。
When the 9 elements(Fe,Co,Ni,Cu,Pb,Zn,Ga,Ge and Cd)in red soil were determined by ICP-MS,the matrix elements Ar,N and O in the argon plasma torch formed polyatomic ions,which would produce strong mass spectral interference to the determination of Fe.The mass fraction of Fe in the red soil in Yunnan is often more than 10%.Therefore,the sensitivity of trace elements such as Cd,Ge and Ga should be ensured while the background signal and signal strength of Fe should be reduced as much as possible.The optimum working conditions for the determination of these elements by kinetic energy discrimination(KED)collision technique were studied.In order to avoid the loss of Ge volatilization in sample decomposition,HNO 3-HF-H 2O 2 was used to decompose samples,Rh and Ir were used as internal standard elements to eliminate the non-mass spectral interference,and the correction formula was used to eliminate the mass spectral interference.The analysis of standard substances and practical tests showed that KED mode could significantly reduce the background interference of Fe and eliminate the oxide interference of Fe on Ge.When the Co/ClO ratio was 10.6,Fe could obtain the best signal-to-background ratio,and other trace elements could also guarantee good sensitivity and accuracy.
作者
侯鹏飞
江冶
曹磊
Hou Pengfei;Jiang Ye;Cao Lei(Geological Survey of Jiangsu Province,Nanjing 210018,Jiangsu,China)
出处
《地质学刊》
CAS
2020年第1期218-222,共5页
Journal of Geology
基金
中国科技部国家重点研发计划项目“长江三角洲重金属污染土壤成分分析标准物质研制”(2016YFF020110303)资助。
关键词
红壤
ICP-MS
动能歧视
云南
red soil
ICP-MS
kinetic energy discrimination
Yunnan
