水浴消解-冷原子荧光法测定植物总汞的消解体系选择

Selection A Water Bath-Based Digestion System Combined with Cold Vapor Atomic Fluorescence Spectrometry to Determine Total Mercury in Plants

为优选简便快捷和测试可靠的植物总汞湿法消解方法,本文以植物标准物质GSB-11(柑橘叶)、NIST-1515(苹果叶)为研究对象,比较了5种水浴酸消解方法以及消解后加入和不加入Br Cl、NH_(2)OH·HCl对植物总汞测定的回收率差异。结果表明,采用逆王水(HCl∶HNO_(3)体积比1∶3)95℃水浴3 h消解植物样品,消解后不加入Br Cl、NH_(2)OH·HCl测定植物总汞含量的方法最优,能实现大批量样品消解,一次消解约100个;操作简单快速,无需调配添加Br Cl、NH_(2)OH·HCl以及静置消解液等;测定结果准确,总汞回收率为99.6%~101.5%,汞加标回收率为98.1%。逆王水水浴消解法是一种高效、简便、准确可靠的植物总汞测定方法,能满足低汞含量植物样品分析要求。

Choosing a simple,fast and reliable wet digestion method is the key to determine the total mercury in plants.In this study,GSB-11(citrus leaf)and NIST-1515(apple leaf)were used as standard materials,and the recovery rates of their total mercury were compared with five water-bath acid digestion methods with and without the BrCl,NH_(2)OH·HCl treatment.The results showed that the optimization procedure is as follows,the plant samples were digested with inverse aqua regia(HCl∶HNO_(3) volume ratio 1∶3)in a 95℃water bath for 3 h,and no Br Cl and NH_(2)OH·HCl were added after the digestion.The advantages of this method are as follows:1.It can digest a large number of samples,e.g.100 samples at a time.2.The operation process is simple and quick,without adding BrCl,NH_(2)OH·HCl,and standing digestion so-lution.3.The measurement results are accurate,with the total mercury recovery rates being from 99.6%to 101.5%,and the mercury recovery rate for the mercury-spiked standard substance being 98.1%.In summary,the inverse aqua regia water bath digestion is an efficient,simple,accurate and reliable method for the determination of total plant mercury,which meets the analysis requirements of low mercury content plant samples.