苦丁茶中15种金属元素和16种稀土元素的电感耦合等离子体质谱法

Determination of 15 metal elements and 16 rare earth elements in Kudingcha by inductively coupled plasma mass spectrometry

目的建立微波消解-电感耦合等离子体质谱法测定大叶和小叶苦丁茶中铅、镉、镍、砷、汞、铬、铝、铜、硒、钒、锰、锂、锑、钡、锡等金属元素以及16种稀土元素的含量。方法用微波消解-电感耦合等离子体质谱法(ICP-MS)测定苦丁茶中15种金属和16种稀土元素,以姥、锗、铟元素作为内标来校正样品的基体效应和仪器信号漂移可能对测试过程的影响。结果在优化条件下,苦丁茶样品中各元素的检出限为0.003~0.700μg/L,加标回收率为91.5%~104.3%,相对标准偏差为0.65%~2.65%,小叶苦丁茶中铅含量明显大于大叶苦丁茶,而镉、铝、锰、钡含量大叶明显高于小叶,镍和铬含量大叶略高于小叶。结论该测定方法简便、快速、准确,适用于茶叶类样品中多元素的快速检测。

Objective To establish a method for the determination of contents of lead,cadmium,nickel,arsenic,mercury,chromium,aluminum,copper,selenium,vanadium,manganese,manganese,lithium,antimony,barium,tin and 16 rare earth elements in large-leaved Kudingcha and small-leaved Kudingcha by inductively coupled plasma mass spectrometry. Methods The contents of 15 metals and 16 rare earth elements in Kudingcha were determined by microwave digestion-inductively coupled plasma mass spectrometry(ICP-MS). The matrix effect of the samples and the influence of the instrument signal drift on the test process were corrected with the internal standard of rhodium,germanium and indium. Results Under the optimum conditions,the detection limits of the elements in Kudingcha were 0.003-0.700 μg/L,the recovery rate was 91.5%-104.3%,and the relative standard deviation was 0.65%-2.65%. The lead content in small-leaved Kudingcha was significantly higher than that in large-leaved Kudingcha,while the contents of cadmium,aluminum,manganese and barium in large-leaved Kudingcha were significantly higher than those in small-leaved Kudingcha,and the contents of nickel and chromium in large-leaved Kudingcha were slightly higher than those in small-leaved Kudingcha. Conclusion The method is simple,rapid and accurate,and is suitable for rapid determination of multi elements in tea samples.