基于同步辐射X射线荧光光谱和X射线吸收近边结构谱研究铅锌矿区浮萍中砷的耐受机制

发布时间：2018-05-21 21:26

  本文选题：浮萍 + 砷　； 参考：《分析化学》2017年05期

【摘要】：水生植物浮萍能够富集高浓度的砷,是植物过滤修复技术的代表,其耐受机理备受关注。本研究利用同步辐射X射线荧光光谱(Synchrotron radiation X-ray fluorescence,SRXRF)和X射线吸收近边结构谱(Xray absorption near edge structure,XANES)技术,开展了铅锌矿区天然富砷浮萍样品中砷元素的微区分布和形态特征研究。微区SRXRF分析了两个单片浮萍样品FP1和FP2,单点扫描时间分别为5 s和2 s,光斑尺寸分别为70μm×80μm和100μm×100μm;对FP2样品选择了6个位置进行了微区XANES单点形态分析,扫描的能量范围为11.81~11.96 keV;整体XANES形态分析是针对压片的浮萍样品,扫描的能量范围为11.67~12.27 keV。结果表明,浮萍样品整体和微区XANES数据均表明砷形态为As(Ⅲ);SRXRF微区分析发现浮萍中砷元素具有显著的叶脉分布特征,在一定浓度范围内,砷并不扩散到进行光合作用的叶肉中,有利于减轻砷对叶片的毒害作用,可能是浮萍耐受砷的一个保护机制。
[Abstract]:The aquatic plant duckweed can enrich high concentration of arsenic, which is the representative of plant filtration and repair technology, and its tolerance mechanism has attracted much attention. In this study, synchrotron radiation X-ray fluorescence spectroscopy (Synchrotron radiation X-ray fluorescence X RF) and Xray absorption near edge structure (XANES) techniques were used to study the microdistribution and morphological characteristics of arsenic in natural arsenic rich duckweed samples in lead-zinc mining area. Two samples of duckweed, FP1 and FP2, were analyzed by SRXRF. The scanning time of single spot was 5 s and 2 s, and the size of spot was 70 渭 m 脳 80 渭 m and 100 渭 m 脳 100 渭 m, respectively. The energy range of scanning is 11.81 ~ 11.96 Kev and the energy range of scanning is 11.67 ~ 12.27 Kev. The results showed that the total and microregional XANES data of duckweed samples showed that the arsenic morphology was as (鈪，

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