贵州典型土壤-茶树系统中稀土元素含量特征

摘要

采用ICP-MS法同步研究了黔北(湄潭县核桃坝、凤冈县田坝),黔东南/黔南(雷山县雷公山、都匀市螺蛳壳)区域典型的土壤-茶树系统中的16种稀土元素含量特征. 结果表明,稀土元素(Rare Earths Elements,REEs)在各土壤-茶树系统均有分布,在黔北地区样品中相对较高、黔南都匀地区最低. 在不同的土壤-茶树系统中,REEs总量自下而上均呈递减的趋势,土壤REEs总量明显高于茶树,茶树地下部分高于地上部分.土壤、茶树样品中16种稀土元素的分布特征较为相似,均以轻稀土元素Ce、La、Nd为主,重稀土元素Y也有较高含量. 茶树中Ce、Eu、Sc、Gd元素的含量多高于土壤,而La、Nd、Pr等元素含量明显低于土壤. 球粒陨石标准化结果表明茶树叶片中Eu元素存在正异常. 研究结果可为深入分析贵州茶叶质量安全风险提供基础数据.%Contents of rare earth elements (REEs) in typical soil-tea plant system which located in north of Guizhou province (Hetaoba of Meitan county,MT and Tianba of Fenggang county,FG) and south/southeast Guizhou province (Leigong-shan of Leishan county and Luosike of Duyun county) were studied by ICP-MS method. REEs were founded in each "soil-tea plant" system,which was higher in north of Guizhou. REEs in soils were significantly higher than tea plant. REEs in be-lowground part were also higher than aboveground part of tea plant. The similar characteristics of 16 types of REEs were ob-served in each "soil-tea plant" system,which was dominated by Ce,La and Nd. The percentage of Ce,Eu,Sc,Gd in tea plant was higher than soil, while the percentage of La,Nd and Pr in tea plant was lower than soil. Results of chondrite normalized showed a positive europium anomaly in tea leaf samples. The results provided basic data to safety risk assessment of Guizhou tea products.