土壤中铅、镉、铬测定方法的研究

Study on the Determination Method for Pb,Cd,Cr in Soil

为建立一种利用快速消解原子吸收法测定土壤中铅(Pb)、镉(Cd)、铬(Cr)的方法,本文将样品加酸后置于石墨消解仪120℃下消解1 h,冷却后直接用超纯水定容,用原子吸收法进行测定。结果显示,采用1 mL硝酸(HNO3)+1 mL盐酸(HCl)+2 mL氢氟酸(HF)快速消解法与微波消解法的测定值相近,标样测定均在不确定度范围内,相对标准偏差(RSD)均小于5%,回收率为90%~102%。由此可知,此方法前处理操作简单快速,能满足国家标准的测定要求,适用于土壤中Pb、Cd、Cr的测定。

In order to establish a rapid digestion method for the determination of Pb,Cd,Cr in soil with AAS,in this study the soil sample is digested for 1 hour by graphite digestion instrument at 120℃after adding acid.After cooling,the sample is directly volumetrized with ultra-pure water and determined by AAS.It shows that the results of rapid digestion with 1 mL HNO3+1 mL HCL+2 mL HF and microwave digestion are similar.The standard samples are all within the uncertainty range,RSD is less than 5%,and recovery is in the range of 90%—102%.It can be seen form this that the method is simple,rapid and can meet the requirements of national standard.It is suitable for the determination of Pb,Cd,Cr in soil.