The Study On Anion Electrodes Of Three Based On Schiff Base Metal Complexes As Carrier

The ion-selective electrode is a kind of analytical method that can rapidly determine sample continuously with simple equipment, simple handled, wide potentiometric response range and highly sensitive.It has been applied in many departments of industry, agriculture and science technology. The design, synthsis and application of highly selective and sensitive neutral carriers are the main research subjects in the ion-selective electrode studies. As some of the schiff bases and schiff bases metal complexes have special planar structure and feasible Louis acidity, recently, the development of ion-selective electrode obtain prodigious advancement This thesis focused on synthesizing of the Schiff bases and Schiff bases metal complexes, then studied on solvent polymeric membrane (SPM) anion-selective electrodes containing these Schiff bases and Schiff bases metal complexes. The researchs of the thesis are as follows.Partâ… . the study on iodide electrode based on unsymmetrical schiff base metal complexes as carrier.A new highly selective PVC membrane iodide electrode of cobalt(â…¡) complex with unsymmetrical schiff base as neutrual carrier had been studied, which is based on the fact that ethylenediamine reacts to acetylaetone and salicylaldehyde . It displayed a preferential potertiometric response to iodide and an anti-Hofmeister selectivity sequence in the following order: I^->Sal^->SCN^->ClO₄^->SO₃^2->Br^->NO₂^->Cl^->Ac^->NO₃^->SO₄^2-. The electrode exhibits near Netnstian potential response to the iodide with a linear range from 1.0×10^-1 to 1.0×10^-7 mol / L , a detection limit of 3.9×10^-8 mol/L and a slope of-50.7 mV/dec in pH 2.0 of phosphorate bufer solution at 26℃. The response mechanism is discussed with the view of the a.c.impedance technique and the UV spectroscopy . It showed that the anti-Hofmeister behavior of the electrode results from the direct interaction between the central metal and the analyte ion and sterie efect associated with the structure of the carrier . The electrode has the advantages of simplicity , fast response , fairly stability , reproducibility and low detection limit . The electrode is successfully applied to the detemination of iodide in pharmaceuticals and salts with satisfactory results.Partâ…¡. the study on thiocyanate electrode based on salicylaldehyde-4-amino quinizine Schiff base metal complexes as carrier.The metal complexes of salicylaldehyde-4-amino quinizine Schiff base has been synthesized. The potentiometric response characters to anion of the electrodes with above mentioned Schiff bases metal complexes as a neutrual carrier has been studied. It is found that the electrode based on salicylaldehyde-4-amino quinizine copper(â…¡) [Cu(â…¡)-SAMT] exhibited an excellent potentiometric response to the thiocyanate and the anti-Hofmeister selectivity sequence in following order: SCN^->Sal^->ClO₄^->NO₃^-> Cl^->Br^->I^->SO₃^2->NO^2->SO₄^2-. The electrode exhibits near Nernstian potential response to thiocyanate with a linear range from 1.0×10^-1 to 1.0×10^-6 mol/L , a detection limit of 6.3×10^-7 mol/L and a slope of -55.64 mV/SCN^- in pH 4.0 of phosphorate bufer solution at 26℃. The response mechanism of the electrode is discussed in the view of the a.c. impedance technique and the UV spectroscopy . The electrode is successfully applied to the determination of thiocyanate in samples with satisfactory results.Partâ…¢. the study on salicylate electrode based on vanillin-diethylenetriamin Schiff base metal complexes as carrier.The metal complexes of vanillin-diethylenetriamin cobalt(â…¡) [Co(â…¡)-VADTR] and vanillin-diethylenetriamin nickel(â…¡) [Ni(â…¡)-VADTR] has been synthesized. The electrode based on vanillin-diethylenetriamin Ni(â…¡) [Ni(â…¡)-VADTR] exhibited an excellent potentiometric response to Salicylate and an anti-Hofmeister selectivity sequence in following order: Sal^->SCN^->Cl^->I^->ClO₄^->Ac^->NO₂^->Br^->SO₃^2->NO₃^-> SO₄^2-. The electrode exhibits near Nernstian potential response to Salicylate with a linear range from 1.0×10^-1 to 1.58×10^-6 mol/L , a detection limit of 3.98×10^-7 mol/L and a slope of -53.0 mV/Sal^- in pH 5.0 of phosphorate bufer solution at 26℃. The response time (t_95%) is 5～10 s. The response mechanism of the electrode is discussed in view of the a.c. impedance technique and the UV spectroscopy . The electrode is successfully applied to the detemination of Salicylate in pharmaceuticals with satisfactory results.