title: Nafronyl ion-selective membrane electrodes and their use in pharmaceutical analysis.
abstract: A simple potentiometric method is described for the rapid determination of nafronyl-drugs in pharmaceutical preparations such as tablets. Nafronyl ion-selective membrane electrodes with either the nafronyl-dipicrylamine ion-pair complex in 1,2-dichloroethane or the nafronyl-dinonylnaphthalenesulphonic acid ion-pair complex in a PVC matrix as electroactive materials were used. Both electrodes exhibit near-Nernstian responses to protonated-nafronyl activity from 10(-2) to about 10(-5)M, in pH ranges that depend on the nature of the electroactive material used in the membrane. Nafronyl in the mg-range can be determined by potentiometric titration with sodium tetraphenylborate solution, with a relative standard deviation of less than 2.0%. No interference from any excipients in the tablets was observed.
authors.affiliation: Institute of Chemical and Pharmaceutical Research Bucharest. 74351-Sos.Vitan 112, Bucharest-3, Romania.
authors.forename: M S
authors.initials: MS
authors.lastname: Ionescu
authors.forename: V
authors.initials: V
authors.lastname: Badea
authors.forename: G E
authors.initials: GE
authors.lastname: Baiulescu
authors.forename: V V
authors.initials: VV
authors.lastname: Coşofreţ