茶叶及代用茶中多种元素检测结果分析

Analysis of multi-elements in teas and tea substitutes

目的测定杭州市市售茶叶中的Al、V、Cr、Mn、Ni、Cu、Se、Ba、Li、As、Cd、Sb、Hg、Pb共14种元素和代用茶中Cr、Ni、As、Cd、Hg、Pb和Al共7种金属元素含量,并对结果进行分析。方法在杭州地区商店、茶叶市场等随机抽取茶叶样品45份,代茶饮样品51份,采用微波消解法进行样品处理,电感耦合等离子体质谱法测定。结果 5种茶叶中,Al和Mn的检出浓度较高。青茶和黑茶中Al、Mn和Ba的检出浓度均较高,其中Al的最高检出含量是1 855 mg/kg,Mn的最高检出含量是1 461 mg/kg。3种代用茶中,苦丁茶中Cd的含量较高,最高检出浓度为8.6 mg/kg。96份茶叶及代用茶中,超标的金属是Pb、Cd和Cr,超标率为6.25%。结论应当加大对茶叶及代用茶中铝等金属含量的监测力度,做好相关风险预警工作。

Objective To investigate the contents of elemental contents（Al,V,Cr,Mn,Ni,Cu,Se,Ba,Li,As,Cd,Sb,Hg and Pb） in teas and tea substitutes（Cr,Ni,As,Cd,Hg,Pb and Al）,and the results were analyzed.Methods 45 tea samples and 51 tea substitutes were collected from markets and tea markets in Hangzhou for the treatment with microwave digestion and determination by inductively coupled plasma mass spectrometry（ICP-MS）.Results The contents of Al and Mn were much higher than the other elements in 5 tea samples.Olong tea and dark tea were detected with a relatively higher concentrations of Al,Mn and Ba than the other tea and the tea substitute samples.The maximum values of Al were 1 855 mg/kg,and the maximum values of Mn were 1 461 mg/kg.Among the three kinds of tea substitutes,the broadleaf holly leaf contained Cd at a higher concent than the others,and the maximum values of Cd were 8.6 mg/kg.The total exceeding standard rate of 96 samples was 6.25%.The content of toxic metal Pb,Cr and Cd in tea and tea substitute were higher than national standard limits.Conclusion It is necessary to strengthen supervision on the detection of Al and other metal elements in tea and its substitute,and do good job on risk warning.