title: A quinidine-responsive plastic membrane electrode.
abstract: A membrane electrode based on quinidine tetraphenylborate in a PVC matrix is described. The electrode exhibits a rapid and near-Nernstian response in the range 3.5 x 10(-5)-1 x 10(-2) M quinidine sulphate at pH 6-8. In an acidic medium the electrode responds to diprotonated quinidine. In sodium tetraphenylboron (Na TPB) solutions the response is linear in respect of log (TPB-) over the range 10(-4)-10(-2)M . Direct potentiometry and potentiometric titrations are used to determine quinidine in pharmaceutical preparations.
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill, NC 27514, USA.
authors.forename: V V
authors.initials: VV
authors.lastname: Cosofret
authors.forename: R P
authors.initials: RP
authors.lastname: Buck