铬(Ⅵ)与谷胱甘肽作用及其中间态配合物形成的电化学表征
Electrochemical Characterization on the Formation of Chromium(Ⅵ) and Glutathione Intermediates
作者单位
杨培慧 暨南大学化学系广州 510632
中国科学院安徽光学精密机械研究所合肥 230026 
张文豪 暨南大学化学系广州 510632 
赵秋香 暨南大学化学系广州 510632 
蔡继业 暨南大学化学系广州 510632 
摘要: 本文采用电化学方法,对谷胱甘肽(GSH)与重铬酸钾的相互作用及其中间态配合物的形成过程进行研究。结果表明:在pH=5.6的HAc-NaAc缓冲溶液中,GSH浓度为Cr(Ⅵ)浓度5倍以上时,Cr(Ⅵ)与GSH作用完全并形成一新的中间态配合物,该中间态配合物于+0.21 V和+0.36 V(vs SCE)处产生一对新的氧化还原峰,UV-Vis的吸收光谱进一步证明了中间态配合物的形成。该配合物不稳定,在一定时间内缓慢分解,其电化学与UV-Vis光谱动力学信息同步。进一步探讨了GSH与Cr(Ⅵ)作用的电极反应机理。当Zn(Ⅱ)存在于该体系时,Zn(Ⅱ)对中间态配合物的生成和分解过程起着双向催化作用。
关键词: 重铬酸钾  谷胱甘肽  电化学分析  中间态配合物
基金项目: 
Abstract: The interaction between chromium(Ⅵ) and Glutathione (GSH) and the formation of their intermediate complexes were studied by electrochemical method. The results showed that a new pair of redox peaks were obtained at +0.21 V and +0.36 V (vs SCE) in acetate buffer solution (pH 5.6) when the concentration of GSH was five times more than that of Cr(Ⅵ). The electrochemical dynamics revealed that the peaks of +0.21 V and +0.36 V were the redox peaks of the intermediate complex, the conclusion was further confirmed by UV-Vis absorption spcetra. The intermediate complex was unstable and decomposed gradually in a certain period of time. When zinc ion was added to the above solution, both the current of redox peaks and the intensity of the UV-Vis absorbance were enhanced. Therefore, the zinc ion could catalyze the formation and decomposition of the Cr(Ⅵ)-GSH intermediate complex. The mechanism of the electrode reaction was also discussed.
Keywords: potassium dichromate  glutathione  electrochemical analysis  intermediate complex
投稿时间:2004-10-20 修订日期:2004-12-27
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杨培慧,张文豪,赵秋香,蔡继业.铬(Ⅵ)与谷胱甘肽作用及其中间态配合物形成的电化学表征[J].无机化学学报,2005,21(4):495-499.
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