半消解悬浮液进样测定粮食样品中镉、铅、总砷含量

Determination of cadmium, lead and total arsenic in grain samples by semi-digestion suspension injection

对粮食样品半消解条件、悬浮液选择、石墨炉程序升温条件、基体干扰等进行研究,建立了半消解悬浮液进样–石墨炉原子吸收光谱法测定粮食样品中镉、铅与砷含量的方法。结果表明,采用标准加入法,将粮食样品进行低温半消解,加入悬浮溶液(0.2%硝酸+0.1%Triton X–100),石墨炉程序升温增加了450℃步骤在空气条件下去除样品基体,得到了良好分析结果,镉、铅以及砷的相对标准偏差(RSD)均小于5%,镉、铅以及砷样品检出限分别为0.20、10.4、11.0μg/L。采用该法测定国家大米标准物质的镉、铅以及砷含量与标准物质证书的结果吻合。因此该法适用于粮食样品中镉、铅与砷的快速测定。

The semi-digestion conditions of grain sample,choice of suspension solution,temperature programmed conditions of graphite furnace and interference of matrix were studied.The method to detect the content of Cd,Pb and As in food samples by semi-digestion suspension sample injection-graphite furnace atomic absorption spectrometry was founded.The results showed that by the standard addition method,the sample was semi-digested at low temperature with suspension solution(0.2%HNO3+0.1%Triton X-100).Additional 450℃step of graphite furnace temperature program was increased under air condition to eliminate the sample matrix,the results were satisfied.The relative standard deviation(RSD)of Cd,Pb and As were less than 5%,and their sample detection limit were 0.20,10.4 and 11.0μg/L,respectively.The content of Cd,Pb and As in national rice standard substance detected by above method was the same with the results of standard material certificate.This method is suitable for rapid determination of Cd,As and Pb in food samples.