الفهرس | Only 14 pages are availabe for public view |
Abstract The electrochemical behavior of the halofuginone was investigated on a glassy carbon electrode (GLC) in a phosphate buffer solutions, pH=3.0 -10.0. Cyclic voltammetric (CV) studies indicated that the oxidation process is irreversible and diffusion-controlled. In addition, halofuginone-imprinted polypyrrole films were electrochemically prepared on GLC in aqueous solutions of halofuginone, and NaClO4 as supporting. The halofuginone template molecule was successfully trapped in the polypyrrole (PPy) film where it created artificial recognition sites. After extraction of the template, the PPy film acted as a molecularly imprinted polymer (MIP) for the specific and selective recognition of halofuginone where as the nonimprinted polymer (NIP) film did not exhibit any oxidation peak which demonstrates that the imprinted PPy films are specific towards halofuginone. The effect of pH, monomer and template concentrations, electropolymerization cycles on the performance of the MIP electrode was investigated and optimized. The highest anodic signal of halofuginone was obtained in a phosphate buffer solution of pH 7.0. The calibration curve for halofuginone at MIP electrode has linear region for a concentration range from 7.5 ×10-9 to 1.0×10-5 M, with a detection limit of 2.5×10-9 M. The electrochemical behavior of nicergoline (NIC) was studied under the effect of pH in phosphate buffer solutions supporting electrolytes on SPCE for the electrochemical oxidation of NIC in aqueous supporting electrolytes over a pH range from 3.0 to 10.0. The peak potential of anodic peak of NIC is shifted linearly towards more negative values and peak current also increased up to pH = 4.0 and afterwards decreased with increasing pH values. But peak potential of pH 4.0 showed two peaks separated by. For this was selected pH 8 at measurement process. Cyclic voltammetric studies indicated that the oxidation process is irreversible and diffusion controlled. |