Study On The Interactions Between Copper And8-hydroxyl Quinoline And Its Application In Electroanalytical Chemistry

The copper is widely used as a non-ferrous metal, which is one of the necessary trace element for human body, plants and animals. Trace copper also can regulate the metabolism of human body. The body lacks copper or excess intake the copper all can affect human health. If people lack of copper in the body, which can cause movement and mental disorders, and the hair turned white and other diseases. High amounts of copper will increase level of free radicals, and change the metabolism of lipid, and cause hepatitis, a neurological disorder, etc. In addition, the content of copper in environment is also cause the attention of people. A large number of copper have certain poisonous effect to organisms, so the determination of trace copper in environment, soil and water has very important significance. This paper mainly finish the following work:We research the nature of oxidation and reduction and the reaction mechanism of cooperate of copper and8-hydroxyquinoline by cyclic voltammetry and discuss the coordination situation of the complexes of different proportion and get the electrochemical properties relation curves of different proportion of copper and8-hydroxyquinoline and we optimize the experimental conditions.A carbon paste electrode surface was modified by copper layer electrochemically deposited under formal potential. The modified electrode was set into1×10-3mol/L8-hydroxyquinoline solution and0.5mol/L potassium nitrate. Through the cooperation of copper atomic and8-hydroxyquinoline, we studied the nature of oxidation and reduction and the reaction mechanism of cooperate. Under the optmum conditions, copper atomic and8-hydroxyquinoline forms coordination compounds make the copper atomic oxidation peak negative move. Through calculation, the complexation reaction enthalpy of copper atomic hydrate and8-hydroxyquinoline is1203.5. The complex reaction of copper and8-hydroxyquinoline is easier.The electrochemical method is used in detecting the copper ions in solution by the electrode modified by zinc-8-hydroxyquinoline-sodium hydroxide. In the range of2.5×10-3to2.5x10-7mol/L of the concentration of copper ions, we can obtain the reduction peaks of copper ions at-1.00V. In the range of1.25×10-12to2.5×10-8mol/L of the concentration of copper ions,we can obtain the reduction peaks of the complex of zinc-8-hydroxyquinoline and copper ions at-1.43V and the peak current decrease with the decrease of the concentration. Therefore, this method can be applied to determinate the trace copper in the solution and this method is good selectivity andhigh sensitivity and from other interference ion disruption. The results are basically the same asthe determination of ICP.