Nafronyl ion-selective membrane electrodes and their use in pharmaceutical analysis.
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.
Ionescu
M S
MS
Institute of Chemical and Pharmaceutical Research Bucharest. 74351-Sos.Vitan 112, Bucharest-3, Romania.
Badea
V
V
Baiulescu
G E
GE
Coşofreţ
V V
VV