亚临界水萃取技术检测茶叶中铅、铬、镉、砷4种重金属元素残留量

Determination of lead, chromium, cadmium, arsenic in tea by subcritical water extraction technique

中文关键词:  亚临界水萃取  电感耦合等离子体质谱  重金属元素  茶叶

英文关键词:subcritical water extraction  inductively coupled plasma mass spectrometry  heavy metal elements  tea

中文摘要:

      目的 建立以亚临界水萃取(subcritical water extraction, SCWE)及电感耦合等离子体质谱(inductively coupled plasma mass spectrometry, ICP-MS)检测茶叶中铅(Pb)、铬(Cr)、镉(Cd)、砷(As) 4 种重金属元素残留量的方法。方法 待测茶叶样品在 5 MPa、150 ℃ 的亚临界条件下经提取15 min后, 用ICP-MS测定。结果 各目标物在1~50 mg/kg 范围内线性关系良好, 相关系数均大于0.999。对茶叶基质进行1.0、5.0和10.0 mg/kg 三个水平的加标回收实验, 4 种重金属元素的回收率为 70.19%~113.25%, 相对标准偏差 RSD< 8.2 %。结论 本方法的灵敏度、准确度和精密度均符合重金属元素残留测定的技术要求, 适用于茶叶中重金属元素残留的检测。

英文摘要:

      Objective To develop aninductively coupled plasma mass spectrometry (ICP-MS) method with subcritical water extraction (SCWE) for the determination of heavy metals residues in tea, such as Pb, Cr, Cd and As. Methods Under the extraction pressure of 5 MPa, the test tea sample was extracted with subcritical water at the temperature of 150 ℃ for l5 minutes and then was determined by ICP-MS. Results The calibration curves showed a good linearity in the range of 1~50 mg/kg with r≥0.999. The recoveries of 4 harmful elements spiked in the tea at three levels of 1.0, 5.0, 10.0 mg/kg were from 70.19% to 113.25% with the relative standard deviations (RSD) lower than 8.2%. Conclusion The sensitivity, accuracy and precision of the method could meet the technical standard of heavy metals residues determination. The method can be applied to the determination of heavy metals residues in tea.