不同消解方法测定土壤中重金属含量的研究

Study on the detection of heavy metal content in soil with different digestion methods

影响土壤重金属测定结果准确性的关键是消解。以两种土壤标准样品为试材,比较研究微波消解、高压消解、石墨消解和电热板消解四种不同消解条件,同时对不同类型土壤中Cr、 Ni、 Cu、 Pb、 Cd、 Zn六种重金属测定结果进行对比分析。结果表明:四种消解方法的测定值均在标准值范围内,但不同酸体系及消解时间会对结果的稳定性有一定的影响。在实际的消解过程中应根据土壤中待测金属元素的理化特性、种类、含量以及样品的数量来选择消解方法。

Digestion method is the key step to affect the results accuracy of detection of heavy metal in soil. To compare the accuracy of different digestion treatment methods, microwave digestion, high pressure digestion, graphite digestion and electricity-plate digestion methods were adopted to digest two types of standard soils, while detecting Cr, Ni, Cu, Pb, Cd and Zn in different soil samples with four digestion methods. The results indicated that all four pretreatment methods were acceptable to determination the metals content in soils, but the different acid system and the digestion time had some influence on the stability of the results. In the actual digestion process, we should choose the digestion method based on the soil of the metal physical and chemical properties, types, content and the number of samples.