PM10中重金属的提取方法及生物可利用性研究

分别运用模拟生物提取法与化学连续提取法对PM10标准参考样品城市源（NIST-1648A）和工业源（BCR-038）中6种重金属（Cd、Co、Cu、Mn、Ni、Pb）质量分数及赋存形态进行分析。其目标是验证2种提取大气固体颗粒物中重金属方法的有效性，并比较2种方法的优缺点，为将来提取PM10中重金属的方法选取提供依据。模拟生物提取法中，使用Gamble溶液模拟人体肺液对 PM10样品进行溶解，实验方法操作较为简单快捷；化学连续提取法中，不同溶解步骤则可确定重金属的不同赋存形态。在需要快速确定 PM10中某种重金属总量时，应优先使用模拟生物提取法。化学连续提取结果表明，城市源PM10中重金属赋存形态分布没有统一规律，工业源PM10中重金属多以残渣态存在。通过对2种来源的PM10样品中重金属生物可利用性分析，城市源的大气颗粒物对人体的毒性更大，其中标准参考样品城市源 PM10中生物可利用性较高的是重金属Cd（BIBio为61.65%±3.45%；BISE为69.02%±3.82%）和Cu，最低的是重金属Co和Pb；标准参考样品工业源PM10中重金属的生物可利用性最高的是Cd（BIBio为27.66%±1.52%；BISE为15.05%±2.13%），而Ni、Co和Pb的生物可利用性较低。

Extraction Method and Bioaccessibility of Heavy Metal in PM10

In this study, simulated biological extraction and chemical sequential extraction were used to analyze the concentration and chemical speciation of 6 heavy metals（Cd, Co, Cu, Mn, Ni, Pb） in two PM10 standard reference samples, urban source （NIST-1648A） and industrial source （BCR-038）. The objective of this study was to verify the validity of the two extraction methods which can provide a basis for the selection of method in the future. In the simulated biological extraction method which can be easily operated, Gamble solution was used to simulate human lung fluid to dissolve the PM10 sample. Although the chemical sequential extraction method has more steps, different chemical speciation of heavy metals can be determined. When the concentration of a kind of heavy metal needs to be determined urgently, the simulated biological extraction method could be a good choice. The distribution of chemical speciation of heavy metals in PM10 of urban source has no obvious rules while the heavy metals in PM10 of industrial source exist in residual condition. With the analysis of the bioaccessibility of the heavy metals in PM10 of two sources, it is concluded that PM10 of urban source is more toxic to human body. The highest bioaccessibility of the heavy metal in NIST-1648A is Cd （BIBio 61.65%±3.45%; BISE 69.02%±3.82%） and Cu, while the lowest is Co and Pb. In BCR-038, Cd （BIBio 27.66%±1.52%; BISE 15.05%±2.13%） has the highest bioaccessibility while the bioaccessibility of Ni, Co and Pb is relatively low.