Studies On Trivalent Metal Caions PVC Membrane Ion Selective Electrodes Based On Hydrazone-containing Benzimidazole Derivativers As Carriers

The thesis concludes three parts:1. Electrochemical performance of Cr(Ⅲ) PVC membrane selective electrode based on (E)-N’-(4-Br-3-methorybenzylidene)-1H-benzo[d]midazobe-2-hydrazide (L1) and (E)-N’-(4-chlorobenzylidene)-1H-benzo[d]midazobe-2-hydrazide (L2) as novel neutral ionospheres were studied. Both electrodes exhibited good Nernstian potentiometric responses for Cr(Ⅲ) ion over wide range10-6～10-1mol/L with slope of21.44and19.30mV/decade, respectively. The detection limits were5.0×10-7and2.2×10-7mol/L. The electrodes responsed rapidly, and the response time was no more than10s. The electrodes could be used for at least1month without any considerable divergences in its potentials. The electrodes show better potential stability and reproducibility. The electrodes with optimum composition have highly selectivity and can work in a certain concentration ethanol solution.. The electrodes were used as the indicator electrode in titration of Cr3+ions and to determine Cr3+ions in waste water and in mixed solution of certain concentration of mixed ions with satisfactory results.2. A PVC membrane sensor for Al(Ⅲ) ions was prepared based on (E)-N’-(4-(dimetlylamino)benzylidene)-1H-benzo[d]midazobe-2-hydrazide (L3) as a carrier. The sensor has a linear dynamic range of1.0×10-7to1.0×10-2mol/L with a Nernstian slope of21.95mV/decade, and a detection limit of1.5×10-7mol/L. The electrode possessed a better selectivity and a strong anti-interference ability, and it can also work in a certain pH range solutions. The electrode was used as an indicator electrode in titration of Al3+ions with EDTA and for the direct determination of Al3+in waste water.3. A new Bi(Ⅲ) ion selective electrode has been prepared based on (E)-N’-(4-hydroxybenzylidene)-1H-benzo[d]midazobe-2-hydrazide (L4) as new carrier. The sensor has a linear dynamic range of1.0×10-7to1.0×10-3mol/L, with a Nernstian slope of19.91mV/decade, and a detection limit of1.9×10-8mol/L. The electrode possessed a better selectivity and a strong anti-interference ability, and it can also work in a certain pH range solutions. The electrode was used as an indicator electrode in titration of Bi3+ions with EDTA and for the determination of Bi3+in aluminum acid bismuth tablets.