PM_(10)中Pb,Cd元素的微波消解提取方案比较

The Comparison of Microwave Extraction Methods on Pb and Cd Elements in PM_(10)

为比较不同消解方案对PM_(10)样品中重金属元素的提取效果,采集PM_(10)样品以不同方案进行消解,而后通过石墨炉原子吸收分光光谱仪对样品中的Pb,Cd进行测定。结果表明,不同方案对PM_(10)中Pb与Cd的提取效率有相似性,所拟合的线性回归分析方程中可决系数R^2=0.908。HF可提高颗粒物的消解程度,且少量HF便可达到良好的消解效果。HCl可强化H_2O_2对样品的消解,有HCl存在时H_2O_2的加入可提高对颗粒物的消解效果,无HCl存在时H_2O_2的加入对提取效果无明显影响。含有高氯酸的消解体系对样品的提取效果优于未添加HClO_4的消解液。HCl的加入可提高提取效率,但对不同元素的促进作用有所差别,对Cd的提取效果略高于对Pb的提取。消解方案4 mL HF+6 mL HNO_3+2 mL HCl+1 mL HClO_4对PM_(10)的消解效果较优。

In order to compare microwave extraction effect of PM10 samples, PM10 samples were collected and digested by different microwave digestion solutions. The contents of Pb and Cd in the samples were determined by using graphite furnace atomic absorption spectrophotometer. The results showed that extraction efficiency of Pb and Cd in PM10 with the different extraction methods were similar, and the correlation coefficient was 0.908 in the fitted linear regression equation. Different methods, the addition of HF, could improve the digestion degree of particulate matter, and a small amount of HF could achieve good effects. In the presence of HC1, the addition of H2O2 could obviously improve the efficiency of digestion. If the method did not using HCl, H2O2 has no obvious effect on digestion of particulate matter. The digestion systems with HClO4 were superior to that without HClO4 on PM10 digestion. The addition of HCL can promote digestion system to extract heavy metals in PM10 However, the promoting effects on different element extraction were different, and the effect of adding HCl on the extraction of Cd was slightly higher than that on the extraction of Pb. The optimum digestion methods on PM10 were 4 mL HF ＋ 6 mL HNO3 ＋ 2 mL HCl ＋ 1 mL HClO4.