Quinidine ion-selective electrode for potentiometric determinations in pharmaceutical preparations

✍ Scribed by Manuel N.M.P. Alçada; José L.F.C. Lima; M.Conceição B.S.M. Montenegro

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 445 KB
• Volume: 283
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(93)85279-s

✦ Synopsis

The construction and evaluation of a quinidine ion-selective electrode, without an inner reference solution, based on an ion exchanger [quinidine tetrakis(4-chlorophenyl)borateI dissolved in 2-nitrophenyl octyl ether and immobilized in PVC is described. The prepared electrode showed a linear response in the concentration range 3 x 10W5-1 x lo-* M in quinidine, with a slope of 57.5 mV per decade when the pH of the solutions was between 5 and 7.5. The reproducibility of the electrode was approximately f 1 mV during a day's work, with a response time of less than 10 s for quinidine concentrations between 10e4 and lo-' M. The electrode was used for the direct potentiometric determination of quinidine in pharmaceutical preparations, giving results with an average recovery of 100.7% and a mean standard deviation of 2.3%.