Preparation and Potentiometric Study of Promethazine Hydrochloride Selective Electrodes and Their Use in Determining Some Drugs

Authors : Nabil S. Nassory, Shahbaz A. Maki And Bashaer A. Al-phalahy, Shahbaz A. Maki

Pages : 539-548

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Publication Date : 9999-12-31

Article Type : Makaleler

Abstract :Promethazine hydrochloride selective electrodes were constructed based on promethazine-phosphotun- gstic acid ion pair in PVC matrix membrane. The plasticizers used were di-butyl phosphate (DBP), tri-n-butyl phosphate (TBP), o-nitro phenyl octyl ether (ONPOE), and di-n-butyl phthalate (DBPH). The electrodes based on DBP, TBP, and ONPOE gave the same linear range between 1 x 10-4 and 1 x 10-1 M, while the one based on DBPH ranged between 5 x 10-4 and 1 x 10-1M. The slopes for linear range ranged from 40 to 56 mV/decade with correlation coefficients lying between 0.9984 and 0.9993. The best detection limit was 2 x 10-5M for the electrode based on DBPH. The standard deviation of potential drift ranged from \pm1 to \pm9 mV. The measurement interferences in the presence of Li+, Na+, K+, Mg2+, Ca2+, Zn2+, Fe3+, Cr3+, and Al3+ were studied using separate and match methods for selectivity coefficient determination. The pH and life time of the electrodes were also studied.
Keywords : Promathazine-HCl selective electrodes, phosphotungstic acid, promethazine determination