四种前处理方法对电感耦合等离子体质谱测定植物样品中27种微量元素的影响  

Comparison of Different Digestion Procedures for Elemental Determination in Plant Samples by Inductively Coupled Plasma-Mass Spectrometry

作　　者：孙德忠[1] 安子怡[1] 许春雪[1] 王苏明[1] 王亚平[1] 

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2012年第6期961-966,共6页Rock and Mineral Analysis

基　　金：中国地质大调查项目(1212010916020)

摘　　要：采用HNO3-HClO4-HF常压消解、HNO3-H2O2-HF高压密闭消解、HNO3-H2O2微波消解,干法灰化后残渣用HNO3-HF-HClO4溶解等四种方法对植物样品进行前处理,使用电感耦合等离子体质谱(ICP-MS)对植物样品中的27种元素进行定量分析,探讨了不同前处理方法对ICP-MS测定植物样品中微量元素的影响。分析结果表明:HNO3-HClO4-HF常压消解使用大量试剂,污染环境,造成空白值高;在常压体系中HClO4的加入能提高样品的消解效率,但赶酸不完全,会造成复合离子对钒和砷的干扰;干法灰化过程中某些元素(硼、汞等)会损失;常压消解和高压密闭消解中加入HF能有效地提高铍、稀土、钇、钛、锑、铀等元素的回收率,但在蒸干赶HF的过程中,会造成硼和汞的损失,并且钢套的生锈会造成铬、镍空白值高。尽管没有一种方法能适用于所有元素的分析,但相比较而言,HNO3-H2O2微波消解体系操作简单,大部分元素(除铍、钛、锑、铋、稀土)能得到满意的结果,精密度(RSD)均小于10%(n=10),相对误差(RE)为-4.6%～13.6%。The overall aim of this study was to identify the influence of different digestion methods for the determination of trace elements by Inductively Coupled Plasma-Mass Spectrometry （ICP-MS） in various plant samples. Four digestion procedures including HNO3-HC1O4-HF at normal pressure, HNO3-H2O2-HF in a pressurized vessel, microwave-assisted digestion with HNO3-H2O2, and HNO3-HClOg-HF after dry ashing were applied for the decomposition of plant samples. Quantitative analysis for the 27 elements in three Certified National Reference Materials GBW 07603, GBW 07604 and GBW 07605 was measured by using ICP-MS. It was demonstrated that the results of some volatile elements （ Hg, B, etc. ） were significantly lower than certified concentration values, which was consistent with these elements being volatile at high temperatures during ashing. Using a large amount of reagents in normal pressure digestion pollutes the environment, and results in a high blank value. The efficiency of digestion was promoted by using HClO4 in a normal pressure system. However, HC1O4 could not be removed completely nor the interferences to the determination of V and As by the complex ion with Cl-. Using HF in digestion at normal pressure and in a pressurized vessel improved recoveries of the REEs, Be, Ti, Sb and U etc. However, the B and Hg volatilized during the procedure of removing HF with heating. A rusty steel vessel caused high blank values of Ni and Cr. Although none of the methods were good enough to provide accurate determinations for all elements in the Certified Reference Materials, a relatively simple method of HNO3 and H2O2 , digested in a microwave oven yielded the most acceptable results with a precision of less than 1O% RSD and relative error of -4.6% -13.6%, except for Be, Ti, Sb, Bi and REEs.

关 键 词：植物样品 微量元素 样品消解方法 电感耦合等离子体质谱法 

分 类 号：O652.4[理学—分析化学] O657.63[理学—化学]