The Application Of Schiff Base And Schif Base Metal Complexes In The Study Of Ion-selective Electrodes

The ion-selective electrode is a kind of analytical method that can rapidly determine sample continuously with simple structure, simple handled, wide potentiometric response range and highly sensitive, it has been applied in many departments of industry and agriculture and science technology. Design, synthsis and application of highly selective and sensitive neutral carriers are main research subjects in the ion-selective electrode studies. Because some schiff bases and schiff bases metal complexes have special planar structure and feasible Louis acidity, the development of ion-selective electrode obtain prodigiouss advancemen. This thesis focuses on synthsis of the Schiff bases and Schiff bases metal complexes, then studying on solvent polymeric membrane (SPM) anion-selective electrodes containing these Schiff bases and Schiff bases metal complexes.Partâ… of this thesis deals with application of schiff bases metal complexes in solvent polymeric membrane salicylate electrode.The salicylaldehyde-urea copper(â…¡) [Cu(â…¡)-SAU] and salicylaldehyde-urea nickel(â…¡) [Ni(â…¡)-SAU] are synthesized. That electrode based on salicylaldehyde-urea copper(â…¡) [Cu(â…¡)-SAU] displays a excellent potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in following order: Sal^->ClO₄^->F>SCN^->NO₂^->NO₃^->Br^->SO₄^2->SO₃^2->Cl^-. The electrode exhibits near Nernstian potential linear range of 1.0×10^-1～9.6×10^-6mol/L with a detection limit of 8.1×10^-6 mol/L and a slope of -51.4 mV/pSal^- in pH=4.0 phosphorate buffer solution at 25℃. The response mechanism is discussed in view of the A. C. impedance technique. The electrode is applied to samples analysis and the results are consistent with those of the titrimetry method.The 2, 3-Butanedione-Semicarbazide Zinc(â…¡) [Zn(â…¡)-BUSE], 2, 3-Butanedione-Semicarbazide copper(â…¡) [Cu(â…¡)-BUSE] and 2, 3-Butanedione-Semicarbazide nickel(â…¡) [Ni(â…¡)-BUSE] are synthesized. That electrode based on [Zn(â…¡)BUSE] exhibited a excellent potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in following order: Sal^->SCN^->ClO₄^->I^->NO₂^->NO₃^->Cl^->SO₄^2->SO₃^2-. The electrode displayed a linear response for Sal^- in the concentration range of 1.0×10^-1～8.0×10^-7mol/L, with a detection limit of 5.0×10^-7 mol/L and a slope of -57.6 mV/pSal^- in pH 4.0 of 0.01 M phosphate buffer solution at 25℃, The response mechanism was also studied with AC impedance and IR spectroscopic techniques. The electrode was successfully applied to medicine analysis with satisfactory results.Part 2 of this thesis deals with application of the salicylaldehyde-α-naphthylamine metallic complexes in solvent polymeric membrane thiocyanate electrode.The salicylaldehyde-α-naphthylamine Copper(â…¡) [Cu(â…¡)-SANA] and salicylaldehyde-α-naphthylamine nickel(â…¡) [Ni(â…¡)-SANA] are synthesized. That electrode based on [Cu(â…¡)-SANA] exhibited a excellent potentiometric response to thiocyanate and an anti-Hofmeister selectivity sequence in following order: SCN^->Sal^->ClO₄^->I^->NO₂^->NO₃^->Br^->H₂PO₄^->Cl^->SO₃^2->SO₄^2-. The proposed electrode shows the best working concentration range 2.5×10^-6-1.0×10^-1mol/L with a detection limit of 1.0×10^-6mol/L and a near-Nernstian slope of-55.5 mV/pSCN^- in pH 4.0 of phosphate buffer solution at 25℃. It has been successfully used as an indicator sensor to potentiometric titration thiocyanate ion with Ag⁺ ion.Part 3 of this thesis deals with application of the 2,3-butanedione-thiosemicarbazide in solvent polymeric membrane silver electrode.The 2, 3-butanedione-thiosemicarbazide is synthesized and used as the neutral carrier for solvent polymeric membrane silver ion electrode which explored good selectivity toward silver ion. The membrane electrode exhibits near Nernstian potential linear range of 3.0×10^-6～1.0×10^-2mol/L with a detection limit 1.0×10^-6 mol/L and a slope of 52.6 mV/pAg⁺ in pH 3.0 at 25℃. The electrode exhibited good selectivity toward silver ion with respect to the familiar cations. The response mechanism was discussed in view of the AC impedance technique. The electrode can be applied to the recovery of determination successfully.