Preparation and Potentiometric Study for Promethazine Hydrochloride (Paperback)

Electrodes for the determination of promethazine hydrochloride based on PVC membrane were prepared based on the use of ion pair (promethazine-phosphotungstic acid) with the following plasticizers: Di-butyl phosphate (DBP), Tri-butyl phosphate (TBP), O-nitrophenyloctyl ether (ONPOE), and Di-butyl phthalate (DBPH). The properties of these electrodes were studied, including: slope, correlation coefficient, concentration range, detection limit, pH effect, and life time. The statistical treatments were applied for the results that include: relative standard deviation (RSD), relative error (RE), mean error, confidence limit for concentration, and confidence limit for potential. The electrodes (A, B and C) based on DBP, TBP and ONPOE respectively, gave a same linear range from 1x10-1 to 1x10-4 M but for electrode D based on DBPH gave the linear range from 1x10-1 to 5x10-4 M. The slopes are (40.58, 39.82, 51.52 and 56.17) mV/decade, with the correlation coefficients are (0.9984, 0.9988, 0.9991 and 0.9993), and the limit of detection 3.5x10-5, 5x10-5, 5.5x10-4 and 2x10-4 M respectively