土壤样品中重金属元素前处理技术探讨

Discussion on Pretreatment Technology of Heavy Metal Elements in Soil Samples

土壤样品常用前处理体系:酸消解法和熔融法。酸消解法包括敞开式酸消解和高压密闭消解法,主要讨论HNO4+HClO4+HF+HCl常压消解体系、HNO4+HF密闭罐消解体系和HNO4+HCl+HF微波消解体系。通过对三种消解体系的消解效果(检出限、准确度和重复性)进行分析,三种消解体系都能满足当前土壤中重金属的检测需求,电热板消解和密闭罐消解用酸量大,产生大量的酸雾,对操作者的健康和环境有影响,消解时间长且敞口消解容易交叉污染。微波消解法简捷、快速、基体效应小,但一次消解样品数量少,仪器价格昂贵。

Soil sample pretreatment system: acid digestion and melting. Acid elimination methods include open acid digestion and high pressure closed digestion. This paper mainly discusses HNO4 + HClO4 + HF + HCl atmospheric pressure digestion system, HNO4 + HF closed tank digestion system and HNO4 + HCl + HF microwave digestion system. Through the analysis of the digestion effect(detection limit, accuracy and repeatability) of the three digestion systems, the three digestion systems can meet the detection needs of heavy metals in the current soil, and the amount of acid used for the digestion of electric heat plates and closed tanks is large. A large amount of acid fog has an impact on the operator's health and environment, and the elimination time is long and the exposure to the solution is easy to cross pollution. The microwave elimination method is simple, fast, and the matrix effect is small, but the number of single digestion samples is small and the instrument is expensive.