The Study Of Electrochemistry And Electroanalytical Chemistry For Folic Acid And Uric Acid

It is very important for the research of bio-molecules in electrochemical properties and electroanalytical methods. More recently, a higher requirement, in situ analysis, is put in face for electro-analyst. The first of all for in situ analysis is the microelectrode used and high sensitivity methods. In this thesis, we have researched new methods of determinations for folic and uric acids in high sensitivity by combining both adsorptive preconcentration and different pulse voltammetry technique. There are three parts in this thesis:1. In this chapter, we investigated about determining of trace folic acid in foodstuff by Different Pulse Voltammetry. In B-R buffer solution (pH 6.59), the folic acid was adsorbed on the electrode surface for preconcentration and than the different pulse stripping scan was performed. The peak currents are linear relationship with folic acid concentration in the ranges of 3.39 X 10-8mol/L-3.73 X 10-7mol/L with non-preconcentration and 6.78 X 10-10mol/L-2.72X 10-8mol/L with preconcentration for 70s. The detected limit is up to 1.0X 10-11mol/L. This method was used in determining of trace folic acid in foodstuff with satisfactory results.2. The uric acid is investigated by Different Pulse Voltammetry at carbon fiber microelectrode (CFME), which is made by us. The CFME is electro-active by a fixed method and it can be used for determining uric acid in the presence of high concentration ascorbic acid. The peak currents are linear relationship with uric acid concentration in the ranges of 6.67 X 10-7mol/L-7.30X 10-6mol/L with detected limit of 2X 10-7mol/L for no preconcentration and 6.70X 10-8 mol/L-8.67 X 10-7 mol/L with detected limit of 2X 10-8mol/L for preconcentration 70s. This method was used in determining of trace uric acid in urine with satisfactory results.3. We found that glycine could be polymerized electrochemically at carbon fiber microelectrode surface. The poly-glycine film modified electrodes possess high stability and good electro catalytic active for uric acid. At this electrode, the peak potentials of uric acid and ascorbic acid are 0.33V and 0.03V respectively. This means that both of them could be determined simultaneously. Based on this point, we have established a method for simultaneously determining uric acid and ascorbic acid. This method was used in determining of trace uric acid and ascorbic acid in urine and serum samples with satisfactory results.