Use of some polymeric Schiff bases for the electroanalytically purposes

In this study, firstly, electrochemical behaviour and reaction mechanisms on the electrode surface of 2-hydroxy-5-bromo-benzaldehyde-polyacrylamide schiff base (PABSB) and 2-hydroxy-5-kloro-benzaldehyde-polyacrylamide schiff base (PACSB) were investigated by using square wave voltammetry (SWV), cyclic voltammetry (CV) and chronoamperomety (CA) techniques in Britton Robbinson buffer solution as supporting electrolyte. Diffusion coefficients for PABSB and PACSB were determined as 3,129 10-8 cm2/s and 3,465 10-7 cm2/s, respectively. At following stage of this study, indol-3-carboxaldehyde polyacrylamide schiff base-glassy carbon (PAISBGC) and indol-3-carboxaldehyde-glassy carbon (In3CGC) modified electrodes were prepared. Processes of surface modification were carried out by electrochemical oxidation for PAISBGC and In3CGC in 0,1 M KCl and 0,05 M tetrabutylammonium tetrafluoroborate consisting asetonitrile medium, as supporting electrolyte, respectively. Prepared modified surfaces were characterized by CV, electrochemical impedance spectroscopy (EIS), reflection absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), ellipsometry and contact angle techniques. Furthermore, two modified surfaces were used for eliminating interferences at the simultaneous determinations of ascorbic acid, uric acid and dopamine by differential pulse voltammetry. The methods were improved for determination of dopamine and uric acid under coexistence of ascorbic acid by using In3CGC electrode and determination of dopamine under coexistence of ascorbic acid and uric acid by using PAISBGC electrode. At In3CGC electrode, LOD and LOQ were determined for dopamine as 1,70×10-6 and 5,70×10-6, for uric acid as 4,99×10-6 and 1,66×10-5 , respectively. At PAISBGC electrode, LOD and LOQ were determined for dopamine as 1,70×10-6 and 5,67×10-6, respectively. Proposed method can be applied to the determination of dopamine in commercial injections formulation and uric acid in human urine samples.