分析化学Issue(10)：1447-1452,6.DOI:10.11895/j.issn.0253-3820.140318
基于SRXRF和XANES研究Pb对玉米种子萌芽的影响及其分布和形态特征
A Study on Distribution and Chemical Speciation of Lead in Corn Seed Germination by Synchrotron Radiation X-ray Fluorescence and Absorption near Edge Structure Spectrometry
摘要
Abstract
Synchrotron radiation X-ray fluorescence analysis technology (SRXRF) can effectively reduce the detection limit for the determination of heavy metal elements, especially suitable for in situ nondestructive analysis of biological samples with low contents. By corn seed germination test, and combining with SRXRF technology, the effects of Pb on corn seed germination and Pb micro-distribution in the corn seed were studied. X-ray absorption near edge structure (XANES ) technique was used to analyze the Pb chemical speciation in different parts of corn seed. The above experiment was taken to understand the absorption and transformation mechanism of Pb by corn seeds. Results showed that germination rate, bud length and root length decreased with increased Pb contents. The analysis of variance showed that P-value of the germination rate, bud length and root elongation of corn seeds which were exposed to different concentration of Pb were 2. 0×10-3, 1. 4×10-4 and 2. 39×10-8, which were all less than 0. 01, therefore there were highly significant differences during these three indicators and the content of Pb. In addition, the inhibition effect on root growth was greater. SRXRF analysis results showed that Pb was mainly enriched in episperm and embryo, which would inhibit embryonic develop into bud and root. The Pb-LⅢ(13035 eV) XANES spectra of all samples include of root, shoot and the different part of seed were the same, they were the same speciation. Linear combination fitting results indicated that the lead phosphate chloride and lead stearate accounted for 74 . 3 %and 24. 2 % respectively, which suggested that the main Pb speciation of corn was lead phosphate chloride which deposited inside of corn, and a few combined with carboxylic to form the organic lead.关键词
玉米/铅/微区分布/化学形态/同步辐射/X射线吸收近边结构Key words
Corn/Lead/Micro-distribution/Chemical speciation/Synchrotron radiation/X-ray absorption near edge structure引用本文复制引用
孙建伶,罗立强..基于SRXRF和XANES研究Pb对玉米种子萌芽的影响及其分布和形态特征[J].分析化学,2014,(10):1447-1452,6.基金项目
本文系国家自然科学基金项目(Nos.20775018,41201527),国家高新技术研究发展计划863项目(No.2007AA06Z124)、中国地质调查局地质大调查项目(No.12120113015200)和国家科技专项"汶川地震断裂带科学钻探工程"0008课题和0003课题第四专项资助 （Nos.20775018,41201527）
