title: Energy-dispersive and x-ray photoelectron spectroscopy and electron microscopy of new quininium-plastic membrane electrodes.
abstract: New quininium (Qn) plastic membrane electrodes of the conventional type were constructed and characterized. They are based on incorporation of Qn-reineckate (QnRn) ion-pair, Qn-phosphotungstate (Qn3-PT), or Qn-phosphomolybdate (Qn3PM) ion associate into a poly(vinyl chloride) membrane. The electrodes are selective for Qn and have been successfully used for the determination of Qn2SO4 in pharmaceutical tablets. Nevertheless, they showed, as almost all other ion-selective electrodes, limited life times. Energy dispersive- (EDS) and X-ray photoelectron spectroscopy (XPS), as well as electron microscopy were applied to investigate the cause of this limitation in the life times of the electrodes. The results indicated that the electrodes lose their activity after prolonged soaking as a result of leaching of the ion exchanger from the membranes into the test solution in addition to deformation at the surface of the expired electrode.
authors.affiliation: Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait. ashoukry@kuc01.kuniv.edu.kw
authors.forename: Adel F
authors.initials: AF
authors.lastname: Shoukry
authors.forename: Hayat M
authors.initials: HM
authors.lastname: Maraffie
authors.forename: Laila A
authors.initials: LA
authors.lastname: Al-Shatti
mesh_terms: D002412:Cations; D004566:Electrodes; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D010969:Plastics; D011143:Polyvinyl Chloride; D011199:Potentiometry; D013057:Spectrum Analysis; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D002412:Cations; D010969:Plastics; D011143:Polyvinyl Chloride