Transient signals with an Antimony(V) ion-selective electrode: The relative signal return rate as a selectivity...

The dynamic response of a Sb(5+) ion-selective electrode based on 1,2,4,6-tetraphenylpyridinium hexachloroantimonate(V) to different ions, ClO(-)(4), HgCl3(-)(3), AuCl(-)(4),TlCl(-)(4), SbCl(-)(6) and tetraphenylborate, in a flow-injection analysis system using a flow-through cell, is studied. The transient signals obtained are different for every ion. A parameter called relative return rate, defined as the ratio of the return rate to peak height, was found to be characteristic for each ion. It was constant up to a concentration range of three decades for those ions with selectivity coefficients K(pot)(sb,j) 1, thus providing a new source of analytical selectivity. Flow injection variables were studied in order to ascertain their influence on this new parameter.