茶叶中稀土元素的萃取分离-ICP-AES法测定

Determination of rare earth elements in tea leaves by ICP-AES with extractionseparation

采用1-苯基-3-甲基-4-苯甲酰基-5-吡唑酮（PMBP）苯溶液萃取分离-ICP-AES法同时测定茶叶中15种稀土元素,消除了基体的干扰,并对样品前处理方法、萃取分离条件进行了考查.方法回收率为： 92.3%～112%,相对标准偏差＜2.5%.在最佳工作条件下,测定了茶叶标准物质（GBW07605）中稀土元素,结果与标准值吻合.

A method for the simultaneous determination of fifteen kinds of rare earth elements in tea leaves by ICP-AES with extraction-separation using benzene solution of 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone was established. The disturbance of matrix will be eliminated. The factors such as the pretreatment method of samples, and the condition of extraction-separation were studied. The recoveries of the method were between 92.3% and 112%. The relative standard deviation was lower than 2.5%. Under the optimum conditions, tea leaf standard sample （GBW07605） was determined. As a result, the contents of rare earth elements in tea leaf standard sample were equal to their reference values. The method is sensitive, fast and accurate, which can be used widely for the determination of rare earth elements in tea leaves.