Novel Ag+ ion-selective electrodes based on two new mixed azathioether crowns containing a 1,10-phenanthroline sub-unit Original Research Article

Novel polymeric membrane (PME) and coated graphite (CGE) silver-selective electrodes based on two recently synthesized mixed azathioether crowns containing a 1,10-phenanthroline sub-unit were prepared. The electrodes reveal a Nernstian behavior over quite wide Ag+ ion concentration ranges with a very low limits of detection (LOD) (i.e. down to 1.0×10−8 M for CGEs and 8.0×10−7 M for PMEs). The potentiometric responses are independent of the pH of the test solution in the pH range 3.0–7.0. The electrodes possess advantages of low resistance, very fast response time, relatively long lifetimes and, especially, good selectivities relative to a wide variety of other cations. The electrodes were used, as indicator electrodes, in the potentiometric titration of silver ion and in the determination of Ag+ in waste water, photographic emulsion and radiographic and photographic films.