基于两种样品前处理方法对比研究小冬克玛底冰川雪坑中痕量元素  

Comparative study of trace elements in snow pit from Xiaodongkemadi glacier in Tanggula mountain based on two sample preparation method

作　　者：熊隆飞 李月芳[1] 李真[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,冰冻圈科学国家重点实验室,兰州730000 [2]中国科学院大学,北京100049

出　　处：《环境化学》2015年第3期520-528,共9页Environmental Chemistry

基　　金：国家自然科学基金面上项目(41276194;40771046;40601021)资助

摘　　要：通过对唐古拉山小冬克玛底冰川雪坑中非季风季节沉积的雪样分别进行酸化处理和消解处理后,利用高分辨扇形磁场等离子体质谱仪(ICP-SFMS)测试了样品中19种痕量元素(Ba、U、Sr、Rb、Tl、Mo、Cs、Pb、Sb、V、Cr、Mn、Fe、Co、Al、Cu、Ti、Li、As)的酸化浓度和总浓度.研究结果表明,痕量元素浓度的变化范围较大,元素Al的最大/最小浓度比为326(酸化浓度)和465(总浓度),元素Pb相应比值为27和48.雪冰中痕量元素的总浓度一般大于该元素的酸化浓度,其中,元素Pb、Fe、Sb、Ba、Al、Ti的酸化浓度占总浓度的平均比值分别为91%、76%、60%、52%、33%和21%.一般地,样品中不溶微粒含量越大,酸化浓度占总浓度的比值越小;不溶微粒含量越小,则相反.对痕量元素的富集系数(EF)分析表明,各元素总浓度EF均值小于酸化浓度EF均值,揭示了用酸化浓度计算EF存在对痕量元素人为来源影响的高估.人类排放是小冬克玛底冰川中痕量元素的来源之一,对于元素Mo和Sb,人类排放估计是主要来源.利用后向轨迹模型模拟出小冬克玛底冰川雪冰中痕量元素在非季风季节主要来源于青藏高原西部及中亚中东地区.The acid leachable concentrations and total concentrations of 19 trace elements （Ba, U, Sr, Rb, T1, Mo, Cs, Pb, Sb, V, Cr, Mn, Fe, Co, A1, Cu, Ti, Li, As） in snow pit samples from Xiaodongkemadi glacier in Tanggula mountain, spanning the non-monsoon season from October 2012 to May 2013, were determined by inductively coupled plasma sector field mass spectrometry （ICP- SFMS）. Results indicate that there were considerable variations in both concentrations. The ratios of Max/Min in acid leachable concentrations of A1, Pb are 326 and 27, while those in total concentrations are 465 and 48. The total concentrations of most trace elements are higher than acid leachable concentrations, and the average ratios between acid leachable concentrations and total concentrations of Pb, Fe, Sb, Ba, A1, Ti are 91%, 76%, 60%, 52%, 33% and 21%, respectively. Generally, samples with higher contents of insoluble dust have lower ratios of acid leachable concentrations to total concentrations, whereas lower contents of dust with higher ratios. Enrichment factors （EF） show that the average EF values of acid leachable concentrations of trace elements are higher than the average overestimated contribution of some trace acid leachable concentrations. Human Xiaodongkemadi glacier, especially for sources of trace elements due to human EF values of total concentrations. This will result in elements from human emissions through the EF values of emission is one source for some trace elements in Mo and Sb based on EF values analysis. The potential emissions in Xiaodongkemadi glacier during non-monsoon season are located in the western Tibetan Plateau, Central Asia and the Middle East simulated by backward air trajectories.

关 键 词：痕量元素 总浓度 酸化浓度 小冬克玛底冰川 粉尘 人类排放 

分 类 号：X131.2[环境科学与工程—环境科学]