火焰原子吸收光谱法测定陕西绿茶和黑茶中的微量元素

Determination of Trace Elements in Green Tea and Black Tea from Shaanxi by Flame Atomic Absorption Spectrometry

以陕西茶庄中常见的4种茶叶(3种绿茶和1种黑茶)为研究对象,采用高氯酸-硝酸(1∶4)混酸对样品进行消解,利用火焰原子吸收光谱法测定并比较了陕西绿茶和黑茶中6种微量元素(Ca、Cu、Fe、Mg、Mn、Zn)的含量。结果表明,陕西绿茶和黑茶中均含有丰富的人体必需的微量元素,但不同种类的茶叶中所含微量元素有一定的差异,4种茶叶中微量元素含量大小依次为Mg>Ca>Mn>Fe>Zn>Cu,各微量元素标准曲线的相关系数在0.9928~0.9995之间,相对标准偏差在0.30%~4.65%之间,加标回收率在92.37%~104.95%之间。该方法简单、快捷,具有较高的精密度与准确度,对陕西绿茶和黑茶的科学饮用、茶饮品的合理开发及深度研究提供了重要的实验依据和理论参考。

Using three kinds of green tea and one kinds of black tea from Shaanxi as research objects,we treated the samples with HClO4-HNO3(1∶4)mixture system,determined and compared the contents of trace elements(Ca,Cu,Fe,Mg,Mn,and Zn)in the green tea and black tea from Shaanxi by flame atomic absorption spectrometry.The results show that the green tea and black tea from Shaanxi are rich in essential trace elements for human body,but the trace elements in different kinds of tea have some differences,and the contents of trace elements in the four kinds of tea follow the order of Mg>Ca>Mn>Fe>Zn>Cu.Moreover,the correlation coefficient of the standard curve of each element is between 0.9928 and 0.9995,the relative standard deviation is between 0.30%and 4.65%,and the adding standard recovery is between 92.37%and 104.95%.The method is simple and fast with high precision and accuracy,which provides an important experimental basis and theoretical reference for the scientific drinking of the green tea and black tea from Shaanxi,the rational development and in-depth research of tea beverage.