高分辨电感耦合等离子体质谱仪测定中亚山地冰川雪冰中超痕量元素  

Determination of Trace Elements in Snow and Ice by Double Focusing Inductively Coupled Plasma-Mass Spectrometry

作　　者：李月芳[1] 姚檀栋[2] 李真[1] 李忠勤[1] 刘亚平[1] 段建平[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冰冻圈与全球变化研究室,兰州730000 [2]中国科学院青藏高原研究所,北京100085

出　　处：《分析化学》2007年第1期37-42,共6页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No40121101;40631001);百人计划项目(No2004401)资助

摘　　要：在超净实验条件下,利用高分辨电感耦合等离子体质谱仪直接测定雪冰样品中浓度在1ng/L^100μg/L之间的多种超痕量元素Al、Fe、Mn、Co、Cu、Zn、Sr、Sb、Cd、CsBa、Tl、Pb和Bi的实验方法进展。在测定过程中灵敏度的变化可通过监测ArAr质谱峰的变化进行校正,并建立了数学校正公式。以1%HNO3为空白溶液获得了各元素的检出限(ng/L)分别为:Al40、Mn6、Fe40、Co2.74、Cu9.6、Zn20、Sr0.03、Sb0.15、Cs0.04、Ba0.4、Tl0.07、Pb0.8和Bi0.05。利用标准参考物质SLRS-4对测试方法的准确度进行了评价。研究了在硝酸含量分别为0.5%、1%、2%和4%时雪冰中超痕量元素质谱信号强度的变化特点。测定结果发现,对于污化层样品,当硝酸的含量为1%时痕量元素的质谱信号强度最大;对于非污化层样品,痕量元素的质谱信号强度在硝酸含量为0.5%时较大,但与硝酸含量为1%时的质谱信号强度相比变化率小于10%。结合中亚山地冰川雪冰中痕量元素浓度差别大的特点,确定硝酸在样品中的含量为1%为合适的酸度。并对卓奥友峰和珠穆朗玛峰雪坑样品进行了分析方法的重复性研究。A double focusing inductively coupled plasma spectrometry （ICP-MS） combing with microconcentric-nebulizer was applied to the simultaneous determination of Al, Fe, Mn, Co, Cu, Zn, Sr, Sb, Cs, Ba, Cd, Tl, Pb and Bi in snow and ice in central Asia at the 1 ng/L to 100μg/L level. Variation of sensitivity during determination can be calibrated mathematically through monitoring the peak of ArAr. The limits of detection （LOD） of trace elements based on 3 times of standard deviation on 1% HNO3 as blank solution are as follows （ng/L） ： Al 40, Mn 6, Fe 40, Co 2.74, Cu 9.6, Zn 20, Sr 0.03, Sb 0.15, Cs 0.04, Ba 0.4, Tl 0.07, Pb 0.8 and Bi 0.05. Measurement repeatabilities of trace elements determined on snow samples from southern Tibetan plateau in terms of RSD were also investigated. The accuracy of the analytical method was verified by the analysis of a certified reference material （ SLRS4, riverine water）. The acid effect on the response intensities of trace metals were investigated based on four different nitric acid contents ： 0.5 %, 1%, 2% and4% in samples. The results show that 1% is the appropriate nitric acid （60% Merk ＂Ultrapur＂ HNO3 ） content in samples while higher response intensities of trace elements can be obtained, as well as con- sidering the large range of concentrations of trace elements in snow and ice samples from central Asia.

关 键 词：超痕量元素 酸度实验 雪冰样品 电感耦合等离子体质谱 

分 类 号：P333[天文地球—水文科学]