ICP-MS测定茶叶中微量元素含量及其溶出特性的研究

Investigation of Elemental Concentration and Extraction Rate of Tea by ICP-MS

采用微波消解电感耦合等离子体质谱(ICP MS)测定了碧螺春、乌龙茶、毛峰、茉莉花茶和云南滇红五种茶叶中微量元素的含量,对其中的乌龙茶和碧螺春两种茶叶进行了不同浸泡时间和不同冲泡次数微量元素浸出率的研究.用茶叶标准物质对测定方法的准确度进行验证,结果表明方法的回收率大多介于95%～110%之间,相对标准偏差小于5%.茶叶中不同元素在不同浸泡时间和次数时其溶出特性不同,溶出规律大多可用对数或指数关系描述.

The trace elements in five kinds of tea including Oolong, Biluochun, Maofeng, Jasmine tea and Yunnan red tea were measured with inductively coupled plasma mass spectrometry (ICPMS) after digesting by microwave heating. The different rates of elemental extraction in Oolong and Biluochun made in different time and made for different times were determined. The measuring method was validated running the certificate reference tea (GBW07605) under the same conditions. The recoveries of the elements ranged mostly from 90% to 110%, and the RSDs were within 5%. The metals extracting characteristics could mostly be described with logarithmic or exponential equation.