BCR法提取柴油车尾气颗粒物中金属及生物学有效性分析

Metal Biological Effectiveness Analysis in Particulate Matter from Diesel Engine Exhausts Extracted by BCR Method

目的研究柴油车尾气颗粒物中金属的化学形态,并对各金属进行生物学有效性分析。方法采用BCR三步萃取法对柴油车排放颗粒物进行连续提取,对颗粒物中含量大的金属Zn,Ba和Ti进行化学形态分析,通过公式计算各金属的生物学有效性系数,根据系数对金属的生物学有效性进行评价。结果通过BCR连续提取法和消解法分析颗粒物中金属的化学形态,Zn,Ba主要存在于有机物结合态中,Ti主要存在于残渣态中。通过计算,Zn、Ba的生物学有效性系数k所在范围为:0.2<k<0.8,存在一定的生物学有效性。Ti的生物学有效性系数k所在范围为:k<0.2,存在较低的生物学有效性。结论金属Zn,Ba和Ti在柴油车尾气颗粒物中含量较大,分析其化学形态,其中Ti主要以残渣态存在,Zn,Ba主要以有机物结合态的形态存在。按照生物学有效性系数所在范围得出,Ti存在较低的生物学有效性,Zn、Ba存在一定的生物学有效性。

Objective To investigate the chemical speciation of metals in particulate matter from diesel exhaust,and to analyze the biological effectiveness of metals. Methods The particulate matter from diesel engine exhaust was extracted by BCR three step sequential extraction method and digested by microwave digestion method.The chemical speciation of main metals Ti,Ba and Zn in particulate matters was analyzed,the biological effective coefficient of each element was calculated by a formula,and the biological effectiveness of each metal was evaluated by the coefficient. Results The chemical speciation of Ba and Zn was mainly in organic binding state,and Ti was mainly in residue state. Through calculation,the biological effective coefficient of Zn and Ba was 0. 2 〈 k 〈 0. 8,they were in a certain degree of biological effectiveness. The biological effective coefficient of Ti was k 〈 0. 2,which was in low biological effectiveness. Conclusions The content of metals Zn,Ba and Ti in particulate matter from diesel exhausts was high,and the chemical speciation of Ti was mainly in residue form,Zn and Ba were mainly in organic form. Based on biological effective coefficient,the biological effectiveness of Ti was low,Ba and Zn have had some biological effectiveness.