CAJ | 학술논문

以受不同浓度Pb胁迫下的玉米种子萌芽试验为基础,结合SRXRF研究Pb对玉米种子萌芽的影响和Pb在玉米种子的微区分布特征,利用X射线吸收近边结构技术( XANES)对萌芽玉米种子不同部位中Pb的化学形态进行分析,藉以了解种子对Pb的吸收和转化规律。结果表明,玉米种子的发芽率、根芽伸长量随培养溶液中Pb( NO3)2浓度增加而降低。种子发芽率、平均芽长、平均根长与暴露 Pb浓度间的方差分析P-value分别为2.0×10-3,1.4×10-4和2.39×10-8,均小于0.01,为极显著差异,说明Pb胁迫对种子萌芽和根芽生长造成了极显著影响,且对根长抑制作用更大。 SRXRF分析结果表明,种皮和胚结构是玉米种子富集Pb的主要部位,Pb富集在胚结构中将抑制种子萌芽。各种子样品的Pb-LⅢ(13035 eV)边XANES谱图相同,为同一种Pb形态,拟合结果显示其含74.3%的氯化磷酸铅和24.2%硬脂酸铅,说明Pb主要以氯化磷酸铅的形式沉积于玉米体内,并有少部分以与羧基结合的有机铅形式存在。
이수불동농도Pb협박하적옥미충자맹아시험위기출,결합SRXRF연구Pb대옥미충자맹아적영향화Pb재옥미충자적미구분포특정,이용X사선흡수근변결구기술( XANES)대맹아옥미충자불동부위중Pb적화학형태진행분석,자이료해충자대Pb적흡수화전화규률。결과표명,옥미충자적발아솔、근아신장량수배양용액중Pb( NO3)2농도증가이강저。충자발아솔、평균아장、평균근장여폭로 Pb농도간적방차분석P-value분별위2.0×10-3,1.4×10-4화2.39×10-8,균소우0.01,위겁현저차이,설명Pb협박대충자맹아화근아생장조성료겁현저영향,차대근장억제작용경대。 SRXRF분석결과표명,충피화배결구시옥미충자부집Pb적주요부위,Pb부집재배결구중장억제충자맹아。각충자양품적Pb-LⅢ(13035 eV)변XANES보도상동,위동일충Pb형태,의합결과현시기함74.3%적록화린산연화24.2%경지산연,설명Pb주요이록화린산연적형식침적우옥미체내,병유소부분이여최기결합적유궤연형식존재。
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.