【作者】 许海燕；

【导师】 屠一锋；

【作者基本信息】 苏州大学 ， 应用化学， 2005， 硕士

【摘要】 本文采用循环伏安法、恒电位电解等方法研究了褪黑素（MLT）在金电极上的不可逆氧化。其伏安过程为受弱吸附和扩散共同控制的过程,氧化反应电荷转移数为2。采用线性扫描伏安法对褪黑素进行测定,灵敏度很高,在2.0×10^-10mol/L～1.0×10^-6mol/L浓度范围内,褪黑素氧化峰电流强度与其浓度呈良好线性关系。检测下限可达10^-10mol/L数量级。可用于脑白金胶囊中褪黑素含量的测定。 在硼酸缓冲溶液（pH6.7）介质中,H₂O₂对鲁米诺的电化学发光有敏化作用。MLT因具有对氧自由基的湮灭作用而对此敏化的电化学发光具有淬灭作用,在MLT浓度为1.0×10^-14～7.0×10^-9mol/L范围内,体系的ECL强度随MLT的浓度增加而降低,且具有良好的线性关系,检测灵敏度极高,检测下限可达到1×10^-14mol/L,用于脑白金胶囊中MLT的测定得到满意结果,为MLT的测定提供了另一种灵敏、可靠的测定方法。更多还原

【Abstract】 The irreversible electrochemical oxidation of melatonin(MLT) was studied by cyclic voltammetry and bulk electrolysis with coulometry in this paper. The experimental results have revealed that its electrochemical oxidation was controlled by weakly adsorbing and the diffusion corporately. The number of electron transfer equals to 2. The linear sweep voltammetry(LSV) could be applied in the determination of melatonin with very high sensitivity. In the range from 2.0×10~10mol/L to l.0×10~6mol/L, the current of oxidation peak of melatonin linearly responded upon its concentration. The detecting limit is as low as 10~10mol/L order of magnitude of the concentration. This method could be used in the determination of melatonin in the capsules with satisfactory results.In the borate buffer solution of pH6.7, the melatonin quenched the H2O2 enhanced electrochemiluminescense(ECL) of luminol because of the annihilation to the oxygen free radicals. It could be sensitively determined by this method. In the range from 1.0×10~14mol/L to 7.0×10~9mol/L, the ECL luminous intensity linearly decreased upon the concentration of MLT . The detecting limit is as low as 1.0×10~14mol/L, and the capsule samples have been determined with satisfactory results. It should be another sensitive and reliable method for the determination of melatonin.更多还原