冬春两季大叶种茶叶中稀土元素的含量差异

Concentration Differences of Rare Earth Elements in Large-leaved Tea Leaves in Winter and Spring

为探究生长季节对大叶种茶叶中稀土元素(REEs)含量的影响,以云南省凤庆县3个具有代表性的大叶种茶园(凤山镇、洛党镇和大寺乡)为研究对象,分别采集土壤和茶叶样品(冬茶和春茶),采用微波消解-ICP-MS法对REEs的含量进行测定.结果表明,凤庆县凤山镇、洛党镇和大寺乡茶园土壤中轻重稀土的比值(LREEs/HREEs)分别为3.96、3.67和3.80,无明显差异,总体上呈现出LREEs富集,HREEs分馏;各茶园冬、春两季茶叶中REEs总量不一,冬茶高于春茶.冬春两季茶叶中各REEs含量比值的计算结果显示,季节对茶叶中各REEs含量的影响不一.其中,对Sc、Dy、Y和Er的影响最大,对Gd、Yb、Nd、Pr、Ce、Sm、La、Eu和Ho的影响次之,而对Tb、Lu和Tm的影响则较小.

In order to illustrate the influence of growing seasons on the concentration of rare earth elements(REEs) in Large-leaved tea leaves, the concentration of REEs in soils and tender tea winter and spring leaves, which were collected from three representative tea gardens(Fengshan Town, Luodang Town and Dashi Town) in Fengqing County,Yunnan Province were analyzed by micro wave digestion ICP-MS method. The results showed that the ratios of LREEs/HREEs were 3.96, 3.67 and 3.80 in Fengshan, Luodang and Dashi teagarden soils, respectively showing no obvious difference. On the whole, the LREEs enriched while the HREEs fractionated. The total amount of REEs in winter and spring tea leaves were different in each tea garden, and the concentration of REEs in winter tea leaves were higher than that in spring tea leaves. The calculated results of the REEs concentration ratios in tea leaves of winter/spring showed that the influence of growing seasons on REEs concentration in tender tea leaves were significantly different, among which the effects on Sc, Dy, Y and Er are the most, followed by Gd, Yb, Nd, Pr, Ce, Sm, La, Eu and Ho, but the least are Tb, Lu and Tm.