不同产区及季节铁观音中稀土元素的组成特征研究

目的研究安溪铁观音中稀土元素的组成特征,探索不同产区及季节对铁观音中稀土元素组成的影响。方法采用电感耦合等离子体质谱仪(inductively coupled plasma-mass spectrometry,ICP-MS)对安溪铁观音6个主产区—桃舟乡、祥华乡、大坪乡、虎邱镇、感德镇和西坪镇所产茶叶中的16种稀土元素的含量进行测定,对不同样品中的稀土元素的含量和组成进行分析。结果安溪铁观音中稀土元素含量的检出范围为0.68~15.94 mg/kg,含量平均值为2.64 mg/kg,含量中值为1.73 mg/kg,轻稀土元素与重稀土元素含量的比值为2.4,轻稀土元素含量占稀土元素总量的67.0%~74.4%。样品中稀土元素的含量从高到低依次为:Ce,La,Y,Nd,其他稀土元素。春季和秋季铁观音中稀土元素的含量间无明显差异。结论安溪县不同产区铁观音中稀土元素的总量从高到低依次为:感德镇、虎邱镇、桃舟乡、大坪乡、祥华乡和西坪镇,季节并不影响茶叶对于稀土元素的总富集能力。

Composition characteristics of rare earth elements in Tie Guanyin from different areas and different seasons

Inductively coupled plasma-mass spectrometry (ICP-MS) was used for determination of 16 kinds of rare earth elements in Tie Guanyin which sampled from six major tea-producing regions of Anxi prefecture- Taozhou Town, Xianghua Town, Daping Town, Huqiu town, Gande Town and Xiping Town. The results showed that the rare earth elements of Tie Guanyin were in range of 0.68 mg.kg-1 ~ 15.94 mg.kg-1, with average of 2.64 mg.kg-1 and median of 1.73 mg.kg-1. The ratio of light rare earth to heavy rare earth is 2.4. The ratio of light rare earth accounts for 67.0% to 74.4% of the total rare earth elements. The content of REEs decreased in order of Ce>La>Y>Nd. The content of Ce was significant difference between Taozhou town, Huqiu town, Gande town with Xianghua Town, Daping Town, Xiping Town, and the former was significantly higher than the latter(P<0.05).From the statistical data analysis, the content of the total rare earth elements showed no significant differences in different towns and different seasons (P>0.05).The total rare earth elements is relatively low from Xianghua Town and Xiping Town.