Potentiometric and thermal studies of a coated-wire benazepril-selective electrode.
A coated-wire benazepril-selective electrode based on incorporation of the benazepril-tetraphenylborate ion pair in a poly(vinylchloride) coating membrane was constructed. The influences of membrane composition, temperature, pH of the test solution, and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a benazepril concentration range of 1.26x10(-5) to 0.58x10(-2) M, at 25 degrees C, and was found to be very selective, precise, and usable within the pH range 2.5-9.2. The standard electrode potentials, E degrees, were determined at 20, 25, 30, 35, 40 and 45 degrees C, and used to calculate the isothermal temperature coefficient (dE degrees /dT) of the electrode. Temperatures higher than 45 degrees C seriously affect the electrode performance. The electrode was successfully used for potentiometric determination of benazepril hydrochloride both in pure solutions and in pharmaceutical preparations.
Khalil
S
S
Department of Chemistry, Faculty of Science, Cairo University, Fayoum Branch, 63514, Fayoum, Egypt.
Abd El-Aliem
S
S
D001552:Benzazepines / Q000032:analysis*; D002626:Chemistry, Pharmaceutical; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D011143:Polyvinyl Chloride; D011199:Potentiometry; D012996:Solutions / Q000032:analysis; D013696:Temperature
D001552:Benzazepines; D012996:Solutions; D011143:Polyvinyl Chloride; C044946:benazepril