江西名茶中10种金属元素含量的测定  

Determination of ten kind of metal elements in different varieties of Jiangxi famous tea

作　　者：柯法钧 杨武英 王丹[1,2] 洪艳平 陈薪竹[1,2] 王玉波 KE Fa-jun;YANG Wu-ying;WANG Dan;HONG Yan-ping;CHEN Xin-zhu;WANG Yu-bo(Key Laboratory of Agricultural Products Processing and Quality Control of Nanchang City,Nanchang,Jiangxi 330045,China;Department of Food Science and Engineering,Jiangxi Agricultural University,Nanchang,Jiangxi 330045,China)

机构地区：[1]南昌市农产品加工与质量控制重点实验室,江西南昌330045 [2]江西农业大学食品科学与工程学院,江西南昌330045

出　　处：《食品与机械》2020年第7期72-77,共6页Food and Machinery

基　　金：国家自然科学基金地区基金项目(编号:31660486)。

摘　　要：对K、Ca、Na、Mg、Fe、Cu、Mn、Zn 8种必需元素火焰原子吸收光谱法的最佳工作条件(乙炔流量、空心阴极灯灯流量和燃烧器高度)进行优化,对铅、镉两种有毒元素石墨炉原子吸收光谱法的最佳工作条件(灰化温度、灰化时间、原子化温度及原子化时间)进行优化,绘制各元素的标准曲线,考察方法的检出限和精密度,优化样品前处理条件及测定样品加标回收率,并对江西名茶中对应的10种金属元素的含量进行测定比较。结果表明,建立的各元素原子吸收光谱法在相应浓度区间内线性关系良好,相关系数为0.9918~0.9992,精密度为0.77%~3.32%,检出限为0.004~0.050μg/mL,回收率为99.25%~102.25%,均符合要求。10种金属元素在8种茶叶中的含量差异性显著,其排序基本为K>Mg>Mn>Ca>Fe>Na>Zn>Cu>Pb>Cd;遂川狗牯脑中K、Ca、Fe含量最高,庐山云雾中Na含量最高,靖安白茶中Mg、Zn含量最高,井冈山翠绿中Mn含量最高,武夷红茶中Cu含量最高,8种茶叶中Pb、Cd含量均较低。试验建立的原子吸收光谱法操作简便、干扰较少、灵敏度高,适用于各种茶叶中相应元素含量的测定;8种江西名茶中K、Ca、Na、Mg 4种常量元素和Fe、Cu、Mn、Zn 4种微量元素含量都比较丰富,Pb、Cd两种有毒元素含量均低于国家标准。Firstly,orthogonal test design was adopted to optimize the best working conditions(acetylene flow,hollow cathode lamp flow,burner height)of atomic absorption spectrometry for the eight kinds of essential elements,including potassium,calcium,sodium,magnesium,iron,copper,manganese,and zinc.Single-factor experimental design was adopted to optimize the best working conditions(ashing temperature,ashing time,atomization temperature,atomization time)of graphite furnace atomic absorption spectrometry for the two toxic elements of lead and cadmium.Thereafter,the standard curve of atomic absorption spectrometry for each element under the best working conditions of the instrument was established,and the detection limit and precision of the method were investigated.The sample pre-treatment conditions were optimized.Under the control of the optimal sample pre-treatment conditions,the sample spiked recovery rate was determined,and flame atomic absorption spectrometry of eight essential elements and graphite furnace atomic absorption spectrometry of two toxic elements that meet the requirements of detection were established.Finally,the corresponding ten elements in eight Jiangxi famous teas were determined by these established methods and further compared.The results showed that these established atomic absorption spectrophotometry methods all had good linear relationship in the corresponding concentration range.The correlation coefficients were 0.9918~0.9992,and the precision RSD values ranged from 0.77%to 3.32%,with the detection limits of 0.004~0.050 g/mL and the recovery rates of 99.25%~102.25%.The results showed that some significant differences in the contents of the ten kinds of elements in the eight types of tea were found,with a certain order,i.e.K>Mg>Mn>Ca>Fe>Na>Zn>Cu>Pb>Cd.Suichuan Gougunao tea contains the highest contents of K,Ca,and Fe and Lushan Yunwu tea has the highest Na content.The highest Mg and Zn contents are Jing'an white tea.The highest Mn content is Jinggangshan green tea.Wuyi black tea was found to con

关 键 词：江西名茶 金属元素 火焰原子吸收法 石墨炉原子吸收法 

分 类 号：TS272.7[农业科学—茶叶生产加工] O657.31[轻工技术与工程—农产品加工及贮藏工程]