不同消解方法分析土壤中重金属含量的比较

Comparison of Different Digestion Methods in Analyzing Heavy Metals Content in Soils

采用电热板消解和微波消解2种方式,分别选用2种常用的酸体系对4种类型的土壤进行消解,重点对Cu、Pb、Cr、Zn、Mn 5种重金属元素进行分析。本文选用的4种常用消解方法对标准土样Cu、Pb、Zn含量的测定值均在标准值范围内,2种酸体系的微波消解对Mn含量的测定值都在标准值范围内,Cr含量则只有HNO3+HF+HClO4酸体系微波消解的测定值在标准值范围内。4种方法对标准土、A类土(广西师范大学生物园土)、B类土和C类土(广西荔浦锰矿区的恢复区土和尾矿土)中Cu、Pb和Zn的含量无显著影响,对土中的Cr含量都有显著影响或非常显著的影响,对B类土中的Mn含量有显著影响。总的来说,HNO3+HF+HClO4体系的微波消解对土样中各种重金属都有较理想的消解效果。

Four kinds of soil were digested by electric heating board digestion and microwave digestion with two kinds of acid system respectively. Subsequently,concentration of Cu,Pb,Cr,Zn,Mn in the soils was determinated. The results showed that concentration of Cu,Pb, Zn in the standard soil sample digested by the four methods in good agreement with the reference values. The determinated value of Mn concentration in the standard soil sample digested by the two microwave digestion methods in good agreement with the reference value. Only determinated value of Cr concentration in the standard soil sample digested by microwave digestion method with HNO3＋HF＋HC104 agreed with the reference value. There was no significant difference in the concentration of Cu,Pb,Zn in the standard soil sample,soil A （sampled from biological garden of Guangxi Normal University）,soil B and soil C （sampled from recovery region and tailing region of Guangxi Lipu Manganese mine）. But there was significant difference in the concentration of Cr in the four soils and in the concentration of Mn in the soil B. Conclusively,microwave digestion method with HNO3＋HF＋HC104 was the most ideal method which could digest effectively all of the five heavy metals in the soils.