Study On Modified Electrodes To Determine Vitamines

In this Paper , the preparation and electrochemical characteristics of electrode modified by 2-pyridinamine , amygdalic acid or melamine to determine vitamine C and vitamineBi were described .In chapter 2 The preparation and electrochemical characteristics of electrode modified by 2-pyridinamine are described. The 2-pyridinamine polymer modified electrode has strong electro-catalytic effect on the oxidation of ascorbic acid. The anodic peak potential of ascorbic acid shifted negatively 272mV. A sensitive amperometric response for ascorbic acid was obtained covering a linear range from 4.0# 10-6 to 1.0 # 10-3 mol/L. The modified electrode showed good stability and reproducibility. The electrode was used to the determination of ascorbic acid in vitamin C tablet and tomato. The results obtained by this method is reasonable agreement with those obtained with conventional methods.The chapter 3 described the preparation and electrochemical characteristics of electrode modified by amygdalic acid are described. The amygdalic acid polymer modified electrode has strong electro-catalytic effect on the oxidation of amygdalic acid. The anodic peak potential of ascorbic acid shifted negatively 280mV. A sensitive amperometric response for ascorbic acid was obtained covering a linear range from3.0 #10-6 to 1.0 # 10-3 mol/L. The modified electrode showed good stability and reproducibility. The electrode was used to the determination of ascorbic acid in vitamin C tablet and tomato, and showed promising results compared with conventional methods.In diaper 4 , the preparation and electrochemical characteristics of electrode modified by melamine are described. The melamine polymer modified electrode has . strong electro-catalytic effect on the reduction of VBI. The anodic peak was observed on the cyclic voltammograph. A sensitive amperometric response for Vsiwas obtained covering a linear range from 6.0#10-6 to 1.0#10-3 mol/L. The modified electrode showed good stability and reproducibility. The electrode was used to the determinationof VBI in VBI tablet and VBi injection liquid. The promising results can be obtained compared with conventional methods.Appended document 1 BSA reacts with p-dimethylaminobenzal rhodanine to form a colorful complex in a B-R buffer at pH 3.27 . The maximum absorption wavelength of the complex A. max is 405nm. The peak of the complex has a "violet shift" of 10 nm as compare with that of the reagent. The linear range of the standard curve is 60-138 mg/L for BSA. Experimental results indicate that the method has good secetivity, reproducibility, simplicity.Appended document 2 Human serum albumen(HSA) reacts with beryllon(III) to form a red complex in a B-R buffer at pH 3.6 . The maximum A max is 460 nm . The peak of the complex has a "violet shift" of 80nm as compare with that of reagent The linear range of the standard curve is 20~140 mg/L for HAS. Experimental results indicate that the method has good selectivity, reproducibility, simplicity and a wide concentration range.