密闭消解HG-AFS法测定丹参植株中汞含量

Determination of mercury in Salvia miltiorrhiza by HG-AFS after closed digestion

为评价中江丹参植株汞含量水平、了解汞的植株分布,采用HNO_3-H_2O_2密闭消解、氢化物发生原子荧光法测定来自中江丹参种植基地的12个植株样品中的汞含量。实验优化还原反应条件,通过国家标准物质比较不同消解方法对测定结果的影响及验证方法的准确度和可靠性,密闭消解获得结果的准确度和精密度符合痕量分析要求。方法检出限为0.12μg/L,相对标准偏差为7.8%,样品加标回收率为81.0%~115.0%。丹参根中的汞含量未超过国家药典标准（〈0.2 mg/kg）,部分茎和叶含量超标,植株汞含量分布为叶〉茎〉根。

In order to understand the mercury level and distribution in Salvia miltiorrhiza. The total mercury concentrations in the organs of the plant collected from 12 sites across Zhongjiang were determined by hydride generation atomic fluorescence spectrometry （HG-AFS） after HNO3- H2O2 closed digestion. Reaction conditions of redox were optimized to obtain the highest sensitivity. The different analytical results of reference material digested by open and closed methods were compared. The accuracy,precision and recovery of closed digestion accorded with the requirements of trace analysis. The detection limit, relative standard deviation and recoveries rate of the method were 0.12 μg/L, 7.8%, and 81.0%-115.0% respectively. Mercury content in root was lower than the regulated value of Chinese pharmacopoeia （〈0.2 mg/kg）, but it in partial leaves and stems samples exceeded the value. Mercury distribution characteristics in salvia miltiorrhiza followed concentrations order of leaf 〉stem〉root.