| Popis: |
The SER spectra of thiamine (T) 4′-hydroxythiamine (HOT), thiamine disphoshate (TDP) on silver electrode at acidic and neutral solution have been investigated. The influence of pyruvate (Pyr) on SER spectra at various applied voltages 0 - -0, 65 V has been studied. In the acidic solution T and TDP interact with the surface by means of the heteroatom of N of the pyrimidine and heteroatoms of N and S of thiazolium ring. The characteristic bands at 665, 755, 1210 and 1640 cm −1 are observed in SERS spectra. It is not detected the interaction of N atom of thiazolium ring of HOT with the silver surface. The Cl − ions play an important role in adsorption of these molecules. In the acidic solution Pyr enhances the interaction of thiazolium moiety of TDP with surface and decrease that of HOT. In the neutral solution and applied voltages more positive than> −0,5 V molecules of T derivatives desorptes and Pyr promotes that. The possible mechanisms of the influence of Pyr on adsorption of the T derivatives are discussed. |
