Smith Paula G, Koch Iris, Reimer Kenneth J
Environmental Sciences Group, Royal Military College, P.O. Box 17000 Station Forces, Kingston, ON, Canada K7K7B4.
Sci Total Environ. 2008 Feb 1;390(1):188-97. doi: 10.1016/j.scitotenv.2007.09.037. Epub 2007 Oct 31.
The localization and identification of arsenic compounds in terrestrial plants are important for the understanding of arsenic uptake, transformation and translocation within these organisms, and contributes to our understanding of arsenic cycling in the environment. High performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS), and X-ray absorption near-edge structure (XANES) analysis identified arsenite, arsenate and arsenic(III)-sulphur compounds in leaf, stem and root sections of Rhaphanus sativus (radish) plants grown in both arsenic contaminated mine waste, and arsenic amended liquid cultures. The total arsenic distribution was similar between the plants grown in mine waste and those grown hydroponically. Arsenate was the predominant form of arsenic available in the growth mediums, and after it was taken up by roots, X-ray absorption spectroscopy (XAS) imaging indicated that some of the arsenate was transported to the shoots via the xylem. Additionally, arsenate was reduced by the plant and arsenic(III)-sulphur compound(s) accounted for the majority of arsenic in the leaf and stem of living plants. In this study the application of synchrotron techniques permitted the identification of arsenic(III)-sulphur species which were "invisible" to conventional HPLC-ICP-MS analysis.
陆生植物中砷化合物的定位和鉴定对于理解这些生物体中砷的吸收、转化和转运非常重要，有助于我们了解环境中的砷循环。高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）和X射线吸收近边结构（XANES）分析确定了在受砷污染的矿山废料以及添加了砷的液体培养物中生长的萝卜植株的叶、茎和根部分中的亚砷酸盐、砷酸盐和砷（III）-硫化合物。在矿山废料中生长的植物和水培植物之间的总砷分布相似。砷酸盐是生长介质中主要的砷存在形式，在被根系吸收后，X射线吸收光谱（XAS）成像表明部分砷酸盐通过木质部转运到地上部分。此外，植物会将砷酸盐还原，而砷（III）-硫化合物占活体植物叶和茎中砷的大部分。在本研究中，同步加速器技术的应用使得能够鉴定出常规HPLC-ICP-MS分析“无法检测到”的砷（III）-硫物种。
