ICP-MS法分析信阳毛尖茶中的9种重金属元素

Analysis of 9 Heavy Metal Elements in Xinyang Maojian Tea Using Inductively Coupled Plasma Mass Spectrometry

为了了解不同产区信阳毛尖茶中重金属元素的含量和分布状况,并利用重金属元素对茶叶产地进行判别,采用微波消解样品前处理结合电感耦合等离子质谱法对信阳产区46个茶叶样品中的9种重金属元素进行了测定。结果表明:信阳毛尖茶中铅、镉和铜的平均含量分别为0.875 6,0.042 5和18.855 6 mg/kg,均低于国家规定限量;相关分析结果显示茶叶中9种重金属元素之间存在正相关,表明重金属元素在茶叶富集过程中有较强的协同作用;聚类分析结果表明重金属元素可作为信阳毛尖茶产地识别的重要指标。

The inductively coupled plasma mass spectrometry （ICP-MS） combined with microwave digestion was employed for the determination of 9 heavy metal elements in 46 Xinyang Maojian tea samples collected from different regions in the city of Xinyang in order to evaluate the concentrations of heavy metal elements and relatives of the concentrations with their origin characteristics. The results showed that the concentrations of lead （Pb）, calcium （Cd） and copper （Cu） were 0.875 6, 0.042 5 and 18.855 6 mg/kg, respectively, which were all below the maximum residue limits （MRLs） set by the nation. The correlation analysis showed that there were significantly positive correlation-ships among the 9 heavy metal elements, which indicated that there was synergistic effect occurrence when the heavy metal elements were enriched by the tea plants. The cluster analysis results indicated that the concentrations of the heavy metal elements in the Xinyang Maojian tea samples were important indexes for the identification of their origin characteristics.