土壤-苦丁茶树系统中铅的GF-AAS测定及其分布特性  

THE DETERMINATION AND DISTRIBUTION CHARACTERISTIC OF LEAD IN THE SOIL-KUDINGCHA SYSTEM BY GF-AAS

作　　者：杜兵兵[1] 罗盛旭[1] 李辉[1] 吴良[1] 贾振亚[1] 

机构地区：[1]海南大学热带生物资源教育部重点实验室,海南省石油化工产品检测重点实验室,海南大学材料与化工学院,海口570228

出　　处：《环境化学》2010年第2期310-314,共5页Environmental Chemistry

基　　金：国家自然科学基金(20867001);海南省教育厅高等学校科学研究指导性项目(Hj2009-29)资助项目

摘　　要：采集不同苦丁茶树的根、茎、叶及对应的土壤样品,经过清洗、烘干、研磨等预处理后,采用高压密封罐加热消解,加入磷酸氢二铵作为基体改进剂,通过氘灯扣除背景,以石墨炉原子吸收光谱法(GF-AAS)测定样品中的铅,铅浓度在0.000—60.000ng.ml-1时与吸光度呈现良好的线性关系,相关系数r=0.9999,检出限为0.200ng.ml-1,方法精密度RSD<5%,回收率93%—107%.用上述方法研究土壤-苦丁茶树系统中铅的分布表明,各种苦丁茶树及土壤中铅的分布具有类似规律,即土壤中铅含量远高于茶树中,茶树的地下部分含量分布为:吸收根>主根,地上部分为:枯叶>茎>老叶>嫩叶,其中嫩叶中铅含量远低于限量指标(Pb≤5.0μg.g-1),对茶叶服用的安全性有利.The cleaning, root, stem, leaf and soil samples of different Kudingcha trees were collected, and pretreated by baking, grinding, and high-pressure sealed digestion. To measure Pb by graphite furnace atomic absorption spectrometry （GF-AAS）, ammonium phosphate was added to reduce matrix interferences, and deuterium lamp was used for background subtraction. The linear range of the standard curve was between 0. 000 ng · g-1---60. 000 ng· g-1, linear correlation coefficient 0. 99989, detection limit 0. 200ng · m1-1, RSD 〈 5%, recovery rate 93%--107%. The results of kudingcha samples showed that the distribution of lead was similar in different Kudingcha trees in that the lead content in soil was far more than in Kudingcha trees. The distribution of lead in underground parts of Kudingcha trees was ： absorbing roots 〉 main roots, the distribution of lead in above-ground parts was： dead leaves 〉 stem 〉 old leaves 〉 young leaves. The content of lead in young leaves was far less than the limit（Pb≤5. 0 μg · g-1）, which was favorable for the safety of drinking-tea.

关 键 词：苦丁茶树 土壤 铅 石墨炉原子吸收光谱法(GF—AAS). 

分 类 号：X833[环境科学与工程—环境工程]