王水水浴消解/ICP-MS法测定土壤及水系沉积物中As、Se、Sb、Hg、Bi的适用性研究

Study on determination of As,Se,Sb,Hg and Bi in soil and sediment by ICP-MS with water bath

电感耦合等离子体质谱仪(ICP-MS)具有灵敏度高、分析速度快、多元素同测、线性范围宽等优点,目前测定土壤及水系沉积物样品中As、Se、Sb、Hg、Bi 5种元素尚无其标准分析方法,学者对其能否准确测定样品中Se、Hg尚存争议。实验沸水浴消解/ICP-MS法测定土壤及水系沉积物中As、Sb、Bi的技术指标,探讨Se、Hg实验结果规律及理论原因。结合相关成果,探讨王水沸水浴消解土壤及水系沉积物对ICP-MS、原子荧光光谱仪(AFS)测定As、Sb、Bi的影响,以6个标准物质样品为研究对象,比较了两种方法的技术指标及优势;通过实验和理论,深入剖析ICP-MS测试样品中Se、Hg情况及规律。王水水浴消解/ICP-MS法测定土壤及沉积物中As、Sb、Bi的检出限、精密度和准确度依次为0.2 mg/kg、2.1%~4.3%、95.2%~108%,0.03 mg/kg、1.3%~4.9%、92%~108%,0.005 mg/kg、1.5%~4.5%、87.2%~103%;其采用^(77)Se、^(78)Se、^(82)Se测定结果分别是真值的60~120倍、8~20倍、20~40倍;当W、Hg含量之比小于50时,其能够准确分析样品中Hg。沸水浴消解/ICP-MS测定土壤及水系沉积物中As、Sb、Bi的技术指标,满足相关技术规范的质量控制要求;消解试剂盐酸及样品中Sm、Gd、Dy等引起的多原子离子及双电荷离子干扰,导致ICP-MS不能直接准确测定Se;样品中W产生的氧化物离子干扰,致使ICP-MS测定样品中Hg的结果明显高于真实值,202Hg受[WO]^(+)的正干扰影响比201Hg^(+)更大。

Inductively coupled plasma mass spectrometry(ICP-MS)had the advantages of high sensitivity,fast analysis speed,multi-element simultaneous determination and wide linear range,but there was no its standard analytical method for the determination of As,Se,Sb,Hg and Bi in soil and stream sediment samples at present,and scholars still disputed whether it could accurately determine Se and Hg in samples.The technical indicators of the method,which was determination of As,Sb and Bi in soil and stream sediment by ICP-MS with boiling water bath digestion,was discussed.The law of the Se and Hg experimental results and theoretical reasons was studied.The influence of the aqua regia boiling water bath digestion of soil and water system sediments on the results of ICP-MS and AFS about As,Sb,and Bi,which Combined with related results,was researched.The technical indicators and technical indicators of the two methods were compared through six Certified Reference Materials.The determination result of Se and Hg by ICP-MS was deeply analysed with experiments and theory.The technical indicators of the method detection limit,precision and accuracy of As,Sb,Bi were 0.2 mg/kg、2.1%-4.3%、95.2%-108%,0.03 mg/kg、1.3%-4.9%、92%-108%,0.005 mg/kg、1.5%-4.5%、87.2%-103%,respectively;the measurement results of ^(77)Se,^(78)Se,^(82)Se by ICP-MS were 60-120 times,8-20 times,20-40 times of the true value,respectively;when the ratio of W and Hg content was less than 50,it was able to accurately determinate Hg in soil and stream sediment samples.The method technical indicators of As,Sb,Bi in soil and water system sediments,was satisfied the quality control requirements of related technical specifications;the polyatomic ions and double charge interference,which caused by hydrochloric in digestion reagent and Sm,Gd,Dy,etc.in soil and stream sediment samples,created ICP-MS unable to directly and accurately determine Se.The oxide ion interference,which cused by W in t soil and stream sediment samples,lead to the Hg measurement result of ICP-MS significantly higher than the actual value,202Hg+was more affected by the positive interference of[WO]^(+)than 201Hg^(+).