摘要
主要研究了波长色散X射线荧光(Wavelength Dispersive X-ray Fluorescence,WDXRF)法在测定茶叶中的微量元素的应用。采用WDXRF方法可以对茶叶中微量元素的含量进行快速、无损和精确的分析,且一次可以分析20多种元素的含量。采用硼酸垫底压片制样,制成试样样片,用X射线荧光光谱仪测定试样样片中的元素含量。该方法简便、快捷且准确。实验统计结果显示,相对标准偏差最大Pb元素为0.43%,测量精密度非常好。采用WDXRF方法测定茶叶中微量元素含量,使用SPSS软件中的聚类分析,将茶叶进行分类,对于判断茶叶的归属地和种类提供了科学和客观的技术依据。
Background： Measuring trace elements in tea can determine its nutritional value, verify the authenticity and place of origin, and detect the poisonous and harmful elements remaining in tea due to the application of chemical fertilizers and pesticides. Purpose： In order to reduce the time for sample preparation and the costs of equipment maintenance, wavelength dispersive X-ray fluorescence （WDXRF） spectroscopy was used to determine the trace elements in tea which is rapid, non-destructive and accurate. The contents of more than 20 elements can be measured simultaneously. Methods： Sample pieces were made by the sample preparation method of boric acid rebasing. To avoid the exogenous environmental pollution subjected in the growth of tea, we removed the residual dust of the tea by cleaning it. According to the principle that the standard samples should be similar types with the samples to be analyzed to select standard samples. The curves were built by SuperQ, which contained compiling the measurement conditions, establishing the measurement conditions, checking the angles, determining the measurement times, checking PHD and adding the contents and the names of sample pieces. The accuracy of the method can be obtained by comparing the measured values with the trace element contents of standard samples. The contents of trace elements in tea determined by WDXRF can be used to classify the tea attribution and the tea species through cluster analysis of SPSS software. Results： （1） The results show that the biggest relative standard deviation is 0.43% of Pb, and the precision is very good. （2） Five kinds of tea are taken separately in Fujian and Ytmnan, measured three times with the established working curves. And tree diagram of cluster analysis can be obtained with SPSS software to analyze the measured average values with cluster analysis, coupling method between groups and Minkowski distance measurement techniques. It can be seen that in the tree diagram, when the critical value 2 was 15, the tea
出处
《核技术》
CAS
CSCD
北大核心
2013年第9期9-17,共9页
Nuclear Techniques
基金
国家高技术发展计划(863)项目(2012AA061803)
成都理工大学金景福项目(J03201211H09)资助
关键词
波长色散X射线荧光法
茶叶
微量元素含量
SPSS
茶叶产地
茶叶种类
Wavelength dispersive X-ray fluorescence spectroscopy （WDXRF）, Tea, Content of trace elements, SPSS, Attributions of tea, Types of tea
