茶叶中铅和镉的微波消解-石墨炉原子吸收光谱测定法

Determination of Lead and Cadmium in Tea by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry

目的建立微波消化前处理石墨炉原子化法测定茶叶中的铅和镉的方法。方法采用全自动微波消解仪对茶叶进行消解,加入(NH4)H2PO4基体改进剂消除干扰,通过优化条件进行石墨炉原子化法测定。结果铅、镉的标准曲线相关系数分别为0.999 5和0.999 3,回收率为96.2～104.4%和93.2%～104.9%,样品测定相对标准偏差均小于4%。结论该方法具有简便、快速、准确等优点,可作为茶叶中铅和镉快捷、可靠的检测方法。

[Objective] To establish a method for determination of lead and cadmium in the tea samples by microwave digest pretreatment-graphite furnace atomic absorption spectrometry（GFAAS）. [Methods]The samples were digested by automatic microwave digestion apparatus with（NH4） H2PO4 as the modifier to eliminate the matrix interference before being introduced into the furnace and then optimized conditions determined by GFAAS. [Results]The standard curve correlation coefficient of lead and cadmium were 0.9995 and 0.9993,and the recoveries was controlled between 93.2% and 104.9%.The relative standard deviation was less than 4%. [Conclusion]This method is simple,rapid,reliable and accurate for determination of lead and cadmium in tea samples.