ICP-MS测定土壤重金属元素消解方式的探索  

Exploration of Digestion Method for Determination of Heavy Metal Elements in Soil by ICP-MS

作　　者：孟茹 杜金花 刘云华 罗林涛[1,3] 何克 刘民武 刘博[1,3] MENG Ru;DU Jin-hua;LIU Yun-hua;LUO Lin-tao;HE Ke;LIU Min-wu;LIU Bo(Shaanxi Key Laboratory of Land Consolidation,Xi’an 710075,China;School of Earth Science and Resources,Chang’an University,Xi’an 710064,China;Shaanxi Provincial Land Engineering Construction Group Co.,Ltd.,Xi’an 710075,China;Zhuhai Institute of Urban Planning and Design,Zhuhai 519000,China)

机构地区：[1]陕西省土地整治重点实验室,陕西西安710075 [2]长安大学地球科学与资源学院,陕西西安710064 [3]陕西省土地工程建设集团有限责任公司,陕西西安710075 [4]珠海市规划设计研究院,广东珠海519000

出　　处：《光谱学与光谱分析》2021年第7期2122-2128,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金青年科学基金项目(41602179);陕西省重点研发计划项目(2019SF-245);国土资源调查项目([2019]001);中央高校基金项目高新技术研究支持计划项目(300102278201)资助。

摘　　要：为改进湿法消解有机质含量偏高土壤样品的方法,通过电感耦合等离子体质谱(ICP-MS)对比了双氧水-氢氟酸-硝酸(H_(2)O_(2)-HF-HNO_(3))、盐酸-硝酸-氢氟酸(HCl^(-)HNO_(3)-HF)、王水-逆王水-硝酸-氢氟酸(NO_(2)Cl^(-)H_(2)[(N 3O 8)Cl]-HNO_(3)-HF)、双氧水-盐酸-硝酸-氢氟酸(H_(2)O_(2)-HCl^(-)HNO_(3)-HF)以及烧失量法-硝酸-氢氟酸(LOI-HNO_(3)-HF)5种不同消解体系对国家土壤成分分析标准物质GSS-1a—GSS-8a样品中铜(Cu)、铬(Cr)、铅(Pb)、镉(Cd)、镍(Ni)、锌(Zn)等重金属元素的萃取效率。以^(103)Rh作为ICP-MS测定时的内标元素,不同测定元素选择合适的监测模式,结果表明,设定3℃·min^(-1)升温速率,选择550℃,煅烧恒温时长3 h,冷却后再用硝酸和氢氟酸进行消解时,Cu,Cr,Pb,Cd,Ni和Zn消解效果最好,加标回收率实验结果表明,标准物质测定值与标准值之间无显著差异,加标回收率为91%~105%,表明该方法的准确度和精密度均符合要求,双氧水-氢氟酸-硝酸(H_(2)O_(2)-HF-HNO_(3))体系和双氧水-盐酸-硝酸-氢氟酸(H_(2)O_(2)-HCl^(-)HNO_(3)-HF)体系中由于双氧水受热分解剧烈,消解液易溅出到电热板上导致测试结果偏低;盐酸-硝酸-氢氟酸(HCl^(-)HNO_(3)-HF)体系和王水-逆王水(硝酸-氢氟酸(NO_(2)Cl^(-)H_(2)[(N 3O 8)Cl]-HNO_(3)-HF)消解体系的测试结果稳定性较差,可能是Cl^(-)对仪器的测试产生了质谱干扰,且在敞开体系中,Cl^(-)易与Cr^(6+)形成CrO_(2)Cl_(2)挥发至空气中,致使Cr元素测试结果偏低,因此在消解土壤样品时最好避免大量Cl^(-)的引入。同时将以上方法也应用到采自于大九湖泥炭地高有机质的土壤样品的对比分析,结果均表明烧失量法-硝酸-氢氟酸消解体系消解的更为彻底,且加酸量少、干扰小,测试结果稳定,因此该方法适宜于对大批量有机物含量偏高的样品进行消解。In order to improve the wet digestion of soil samples with high organic matter content,this paper by ICP-MS compared to analyze Copper(Cu),Chromium(Cr),Lead(Pb),Cadmium(Cd),Nickel(Ni)and Zinc(zinc)in national soil component analysis standard materials(GSS-1a—GSS-8a)by five different digestion systems,and they were the H_(2)O_(2)-HF-HNO_(3),HCl^(-)HNO_(3)-HF,HNO_(3)·3HCl^(-)3HNO_(3)·HCl^(-)HNO_(3)-HF,H_(2)O_(2)-HCl^(-)HNO_(3)-HF and LOI-HNO_(3)-HF.^(103)Rh was used as the internal standard element in the determination of ICP-MS,and the appropriate monitoring mode was selected for different determination elements.The results showed that the digestion effect of Cu,Cr,Pb,Cd,Ni and Zn was the best when setting the heating rate of 3℃·min^(-1),calcining at 550℃ for 3 h,and then digesting with nitric acid and hydrofluoric acid after cooling.The results of standard addition recovery experiment shown that there was no significant difference between the measured value and the standard value of the standard substance.The recovery rate of standard addition is 91%~105%,which shown that the accuracy and precision of this method met the requirements.In the hydrogen peroxide-hydrofluoric acid-nitric acid system and hydrogen peroxide-hydrochloric acid-nitric acid-hydrofluoric acid system,the decomposition of hydrogen peroxide is severe when heated,and the digestion solution is easy to splash,resulting in low test results.The test results of hydrochloric acid-nitric acid-hydrofluoric acid system and aqua regia-aqua regia-nitric acid-hydrofluoric acid digestion system are not stable,which may be due to the interference of Cl^(-)on the mass spectrum of the instrument,and in the open system,CrO_(2)Cl_(12) is easy to volatilize during the sample decomposition process,resulting in low Cr content.At the same time,the above methods are also applied to the comparative analysis of soil samples with high organic matter collected from the peat land of Lake Dajiuhu.The result shown that the digestion method of loss on ignition-nitric

关 键 词：土壤 重金属元素 电感耦合等离子质谱 湿法消解 

分 类 号：O433.5[机械工程—光学工程]