【作者】 王晓芳；

【导师】 罗立强；

【作者基本信息】 中国地质科学院 ， 分析化学， 2009， 硕士

【摘要】 本文针对南京市栖霞山铅锌银矿区周围几大类普遍存在的蔬菜（韭菜,水萝卜,菠菜,茼蒿,芹菜,莴苣等）中Pb、Cd、Cr、As等重金属元素污染状况,蔬菜中重金属的富集分布特征开展研究,并在此基础上,文章利用新技术方法就重金属的吸收迁移能力,重金属在蔬菜微区范围的分布趋势,在蔬菜亚细胞结构中分布以及核蛋白中重金属分布的初步情况进行了探讨,结果表明:1样品中重金属与蔬菜中污染物限量标准（GB2762-2005）以及与对应背景样品进行对比,发现除Cu元素外,Pb、As、Cd、Cr和Zn元素都已超出背景值和国家限量指标,其中Pb和As超标率达到了91.7%,其次是Cd元素;叶菜类蔬菜受各元素污染程度大于根茎类蔬菜。2不同蔬菜品种中重金属的含量分布有较大区别,整体上有葱蒜类＞绿叶类＞食用菌类＞白菜类＞薯芋类＞直根类＞茄果类＞豆类的趋势,Pb在叶菜类（葱蒜类和绿叶类）中具有相对强的富集程度。同一蔬菜不同部位中金属的分布特征也不同,萝卜（Raphanussativus）叶中Pb(含量范围为42.120～1.461μg·g^-1)和As平均含量为根(Pb含量范围为3.571～0.279μg·g^-1)的10倍;黄豆（Giycine max（L）Merrill）中重金属质量分数依次是豆叶+豆角皮)豆茎)黄豆皮)黄豆;芹菜中Pb,Cu和Cd含量以根中含量最高,叶中含量次之,而茎中含量最低。3蔬菜对重金属的吸收能力因品种而不同,在蔬菜可食部分对重金属的吸收能力呈:对Pb有:韭菜＞空心菜＞菠菜＞萝卜根;对As的吸收有:空心菜＞菠菜＞韭菜＞萝卜根;对Cd的吸收:菠菜＞空心菜＞韭菜＞萝卜根;对Cr为:萝卜根＞韭菜＞空心菜＞菠菜,对Cu为:空心菜＞菠菜＞韭菜＞萝卜根。此外重金属的吸收迁移能力随元素种类而变化,总体有:Cd＞Zn＞Cu＞Pb,Cd从土壤进入植物的能力最强,更容易对生物系统造成污染。4蔬菜中重金属微区分布主要有,萝卜根横切面主茎和表皮处Pb,As和Cr含量分布较其他部位高.5不同重金属元素在各细胞组分中的分布有一定的差异,其中Pb和Cr的分布为F1＞F2＞F3＞F4,Cd的分布规律为F1＞F4＞F2＞F3,As的分布为F1＞F2＞F4＞F3。Pb和Cr在细胞壁处的分布率分别达到了74.6%和75.06%,As和Cd也主要分布在细胞壁处。6韭菜蛋白质层析过程中出现吸收峰的对应洗脱液中Pb含量有明显的变化特征,初步推出韭菜中不同分子量的核蛋白中金属含量不同,并且通过进一步的凝胶层析实验得到:韭菜,水萝卜和菠菜中核蛋白吸收峰主要出现在40min之后,初步得到这三种蔬菜中核蛋白主要为分子量小于一万的小分子蛋白质。更多还原

【Abstract】 The content of heavy metals(Pb、Cd、Cr、As.et) in vegetables (leek,celery ,radish and spinach.et) contaminated with a Lead-Zinc -Silver(Pb-Zn-Ag)mine in Qixia District in Nanjing were studied in this thesis. Total concentrations of Lead (Pb), Chromium (Cr), Copper (Cu) , Zinc (Zn) , Arsenic (As) and some other elements in vegetables were determined by inductively coupled plasma-mass spectrometry(ICP-MS).The assessment on heavy metal pollution and distribution of heavy metals in vegetables were systematically studied based on total concentrations. furthermore, the min-area distribution, subcelluar distribution and speciation of heavy metals in main vegetables were discussed based on using new technique. Main results are as follows:1. Most of vegetables studied has suffered from pollution of Pb、As、Cd、Cr and Zn, the exceeding standard rate of Pb and As are 91.7%, and Cd is less serioursly. The heavy metal pollution in leave-vegetables are more seriously than rootstalk.2. Among all these kinds of vegetables determined, shallot, garlic and leave-vegetables show the highest content of heavy metals, especially Pb, and bean vegetables the lowest. Besides, there is some tendency of distribution for heavy metals in different parts of one kind of vegetable, for example, the content of Pb, as well as As, in root is ten times as high as that in leaves of raphanus sativus.3. The absorbency of heavy metals differed in various vegetables. In the aspect of absorbtion of Pb, the order was leek>cabbage> spinach>raddish; the rank was cabbage> spinach> leek> raddish to the absorbtion of As; as to the absorbtion of Cd, spinach> cabbage>leek> raddish; the order changed into raddish>spinach> cabbage>leek and cabbage>spinach> leek>raddish in the absorbtion of Cr and Cu. In addition, the absorbency of heavy metals differed in elements.4. The min-area’s distribution of heavy metal in main vegetable samples (such as radish) showed some trend according to intensity counts: in transverse section of radish, the intensity counts of Pb, As and Cr are more high in caulis and cuticle than in other part.5. The sub-celluar distribution of heavy metals were also different.The distribution of Pb and Cr was F1>F2>F3>F4. As to the distribution of Cd and As, the rule was F1> F4 >F2>F3 and F1> F2>F4>F3 respectively.6. The concentration of lead changed as the absorbtion peak of protein of leek. The molecular weight of the protein of leek, raddish and spinach was less than 10000 through forther research.更多还原