2种苦丁茶中重金属及稀土元素含量调查分析

Investigation and analysis of heavy metals and rare earth elements content in 2 kinds of Chinese holly leaf

中文关键词:  苦丁茶  重金属  稀土元素  电感耦合等离子体质谱法

英文关键词:Chinese holly leaf  heavy metal  rare earth element  inductively coupled plasma-mass spectrometry

中文摘要:

      目的 研究大叶苦丁茶和小叶苦丁茶中重金属铬、镉、铅和16种稀土元素的含量情况, 了解苦丁茶重金属及稀土元素摄入的风险。方法 以微波消解法进行样品前处理, 采用电感耦合等离子体质谱仪(inductively coupled plasma-mass spectrometry, ICP-MS)同时检测2种苦丁茶中重金属铬、镉、铅和16种稀土元素, 并将检测结果与食品安全国家标准进行比较。结果 本方法对各元素的检出限为0.012~0.062 μg/L, 加标回收率为94.6%~107.7%, 相对标准偏差为0.3%~6.1%, 该方法经茶叶标准物质(GBW 08513)验证可靠。苦丁茶样品分析表明, 铅、铬和稀土元素在2种苦丁茶中的含量较低, 而大叶苦丁茶镉的含量(2.00~15.73 mg/kg)明显高于小叶苦丁茶(0.05~0.14 mg/kg)。结论 本方法适用于茶叶类样品中多元素污染物快速检测及风险评估, 风险监测数据表明大叶苦丁茶中存在重金属镉摄入性风险。

英文摘要:

      Objective To investigate the content of chromium (Cr), cadmium (Cd), lead (Pb) and 16 kinds of rare earth elements in 2 kinds of Chinese holly leaf (Ilex Kudingcha C. J. Tseng. and Ilex lartifolia Thunb.), so as to reveal the ingestion risk of each element. Methods The samples were digested by microwave digestion system firstly, and then the content of Cr, Cd, Pb and 16 kinds of rare earth elements were detected by inductively coupled plasma-mass spectrometry (ICP-MS), and the results were compared with the national standards. Results The detection limits of the method were 0.012~0.062 μg/L. The spiked recoveries were in the range of 94.6%~107.7%, and the relative standard deviations were 0.3%~6.1%. This method had been verified accurate by the reference material Tea (GBW 08513). Samples analysis demonstrated that the risk of Cr, Pb and rare earth elements was negligible in 2 kinds of Kudingcha. However, the content of Cd in Ilex Kudingcha C. J. Tseng. (2.00~15.73 mg/kg) was extremely higher than that in Ilex lartifolia Thunb. (0.05~0.14 mg/kg). Conclusion This method is suitable for the multi-element determination and risk assessment in tea. Risk monitoring data shows that Ilex Kudingcha C. J. Tseng exists the potential risk of excess intake of Cd.