| 区域大气颗粒物干沉降采集及金属元素分析方法 |
| 摘要点击 3963 全文点击 4967 投稿时间：2009-04-08 修订日期：2009-06-08 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 金属元素 干沉降 代用面 微波消解 ICP/MS 京津冀地区 |
| 英文关键词 trace metals atmospheric dry deposition surrogate surface microwave digestion inductively coupled plasma mass spectrometric (ICP/MS) Jingjinji area |
|
| 中文摘要 |
| 以颗粒物为载体,从大气向水体、土壤和植被沉降的金属元素污染日趋严重.为了解其在京津冀区域的污染程度和沉降规律,利用聚氨酯泡沫膜片（PUF膜）为代用面,在区域内布设10个站点同步采集大气颗粒物干沉降.选择HNO3-H2O2-HF为消解酸体系,建立了微波消解-电感耦合/等离子体质谱（MAD-ICP/MS）测定其中20余种金属元素的方法,并通过分析2种国家标准物质的条件实验确定了优化的分析方案.结果表明,2007～2008年冬季京津冀地区大气颗粒物干沉降通量变化为85～912 mg·（m2·d）-1,其中河北保定地区金属元素沉降通量最高,兴隆最低;北京、天津和唐山市区明显高于郊区站点.地壳元素（Al、Fe、Mn、K、Na、Ca、Mg）干沉降通量变化为151～16 034 μg·（m2·d）-1,明显高于人为源元素（Cu、Pb、Cr、Ni、V、Zn、Ba） 1～3个数量级 [14～243 μg·（m2·d）-1];Zn和Ca分别是区域内干沉降通量最高的重金属和地壳元素,Mo、Co、Cd、As、Be沉降量较少;Pb和Zn出现明显富集. |
| 英文摘要 |
| Interest in atmospheric dry deposition results mostly from concerns about the effects of the deposited trace elements entering waterbody, soil and vegetation as well as their subsequent health effects. A microwave assisted digestion method followed by inductively coupled plasma mass spectrometric (MAD-ICP/MS) analysis was developed to determine the concentrations of a large number of trace metals in atmospheric dry deposition samples with a heavy matrix of polyurethane foam (PUF). A combination of HNO3-H2O2-HF was used for digestion. The experimental protocol for the microwave assisted digestion was established using two different SRMs (GBW 07401, Soil and GBW 08401, Coal fly ash). Subsequently, blanks and limits of detection for total trace metal concentrations were determined for PUF filter which was used for dry deposition sampling. Finally, the optimized digestion method was applied to real world atmospheric dry deposition samples collected at 10 sites in Jingjinji area in winter from Dec. 2007 to Feb. 2008. The results showed that the area-averaged total mass fluxes ranged between 85 and 912 mg·(m2·d)-1, and fluxes of most elements were highest at Baoding and lowest at Xinglong. In addition, the elemental fluxes in urban areas of Beijing, Tianjin and Tangshan were measured to be higher than that in suburb and rural sites .The average fluxes of crust elements (Al,Fe,Mn,K,Na,Ca and Mg) were one to three orders of magnitude higher than anthropogenic elements (Cu,Pb,Cr,Ni,V,Zn and Ba),varying from 151 to 16 034 μg·(m2·d)-1 versus 14 to 243μg·(m2·d)-1. Zinc was the most abundant heavy metal and calcium the highest of the crust elements while the elements Mo,Co,Cd,As and Be deposited less or even could not be detected. The anthropogenic and crustal contributions were estimated by employing enrichment factors (EF) calculated relative to the average crustal composition. The EF values of all elements except Pb and Zn were below 10, suggesting that local soil and/or dust generally dominate in the dry deposition flux. |
|
|
|
