微波消解-原子吸收光谱法测定昭平绿茶中微量元素

茶叶中微量元素的含量分析是茶叶科学的重要研究内容之一,其含量高低对茶叶品质影响较大,因此,有必要对茶叶中的微量元素进行测定。研究建立了以HNO3-H2O2为消解液进行微波辅助消解样品,火焰原子吸收光谱法测定绿茶中铜、铁、锌微量元素含量的方法。实验采用程序升温的方式进行样品消解,回收率高,并且对三种绿茶样品测定结果进行了比较分析。回收率在93.6%101.5%之间,RSD在0.58%3.16%之间;样品中微量元素含量分别为Fe:98.95 177.8μg/g,Zn:45.67 59.29μg/g,Cu:19.7724.22μg/g。此方法测定茶叶中微量元素,可靠、灵敏度高,选择性好,方法简便,且对环境友好,适合常规分析。

Determination of trace elements in zhaoping green tea by atomic absorption spectrometry with microwave digestion

The aanalysis of trace elements in tea is one of the important projects in tea research because of their great impact on the quality of tea.A method to determine trace elements of Cu,Fe and Zn in three kinds of green tea from Zhaoping was proposed.It used microwave assisted digestion with the mixtures of HNO3 and H2O2,and atomic absorption spectrometry detection.When temperature-programmed is used in digestion,higher recovery rates were achieved.The results of three kinds of green tea were comparatively analyzed.The recovery rates of determined elements were from 93.6% to 101.5%.The relative standard deviations for determination of these elements ranged from 0.58% to 3.16%;the content of each trace element in samples is Fe:98.95177.8μg/g,Zn:45.6759.29μg/g,Cu:19.7724.22μg/g.This method can provide a reliable,sensitive,selective,simple and environmental friendly approach in determine trace elements in tea and is suitable for routine analysis.