Flow injection potentiometric determination of amantadine HCl.

New amantadine (Am) ion selective plastic membrane electrodes of both conventional and coated graphite types based on the ion-pair of amantadinium tetraphenylborate (Am-TPB) ion-pair are prepared. The conventional type electrode was fully characterized in terms of membrane composition, life span, pH, ionic strength and temperature. It was applied to potentiometric determination of amantadine in pure state and pharmaceutical preparation under batch and flow injection conditions. The selectivity of the electrode toward a large number of inorganic cations, sugars and amino acids was tested. The solubility product of the ion-pair and the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductimetrically.