土壤中磷的同步辐射X射线吸收近边结构谱测量方法研究

项目名称： 土壤中磷的同步辐射X射线吸收近边结构谱测量方法研究

项目编号： No.11475213

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 郑雷

作者单位： 中国科学院高能物理研究所

项目金额： 100万元

中文摘要： 识别土壤中的各种含磷化合物形态是环境科学研究领域的热点，同步辐射XANES技术是表征土壤中含磷化合物形态和阐明化学反应微观机制的前沿技术之一。本项目拟在北京同步辐射装置4B7A光束线的中能谱学实验站开展土壤样品中磷的K边XANES谱测量方法研究，提高XANES谱的信噪比，以提高土壤样品中含磷化合物种类的相对含量的测量精度。主要包括波长色散探测系统中晶体和探测器的选择及其调节和运动机构设计、数据获取模式研究、吸收谱实验数据质量分析以及衰减片在常规吸收谱测量模式中的选用方法研究等内容。建立一种采用波长色散技术测量土壤中磷的K边荧光吸收谱的实用方法，解决采用能量色散型探测器获得的土壤样品中磷的K边XANES谱数据质量不高的问题，完善土壤中磷化合物种类鉴别的分析方法，探索国内不同地区的土壤中含磷化合物的种类和含量不同的原因。该项研究对揭示国内各种土壤中磷化合物种类的分布规律具有重要意义。

中文关键词： 同步辐射；X射线吸收近边结构谱；土壤；磷

英文摘要： Identifying phosphorus speciation in soils is a hotspot in research field of environment science. Synchrotron radiation-based X-ray absorption near edge structure(XANES) spectroscopy has become one of the frontier technologies for characterizing the speciation of phosphorus in soil and clarifying the microscopic mechanisms of chemical reactions. In order to improve the signal-to-noise of the K-edge XANES spectra of phosphorus in soils, research of a new method of measuring absorption spectroscopy will be performed at the experimental station of beamline 4B7A in Beijing Synchrotron Radiation Facility, which will increase accuracy of the relative concentration of the obtained phosphorus speciation in soils. This research mainly include which kind of crystal and detector will be chosen in detection system based on wavelength-dispersive spectroscopy, the design of motion mechanism and its adjust, the mode of data acquisition, the analysis of data quality of the absorption spectra, and how the attenuators is used in conventional measurement mode of absorption spectrum etc. A feasible and practical method will be constructed utilizing wavelength-dispersive technique to measure the K-edge XANES spectra of phosphorus in soils, which can solve the problem of the poor quality of K-edge XANES spectra measured using energy-dispersive detector of phosphorus in soils and consummate the analysis method of identifying phosphorus speciation in soils, and explorer the reason of different of phosphorus speciation and its concentration in soils of different region in domestic. This project has significant meaning for revealing the distribution law of phosphorus compounds in various domestic soils.

英文关键词： synchrotron radiation;XANES;soil;phosphorus