title: Polymeric membrane sensors for the selective determination of dextromethorphan in pharmaceutical preparations.
abstract: The construction and electrochemical response characteristics of poly(vinyl chloride) matrix ion-selective electrodes (ISEs) for dextromethorphan (DXM) hydrobromide are described. The membranes incorporate ion-association complexes of DXM with reineckate salt {[Cr(NH3)2(SCN)4]NH4} or phosphomolybdic acid [H3(PMo12O40)], as electroactive materials and dioctylphthalate or dibutylsebacate as a plasticizing solvent mediator. The sensors display a fast, stable and linear response with slopes of 54.4 to 59.5 mV/decade at pH 2.5-6.5 and a detection limit of 1.0 x 10(-6) M. Moreover, the sensors exhibit very good selectivity for DXM over opiate alkaloids, as well as organic and inorganic cations. The sensors proved to be useful for the determination of 5.0 x 10(-5)-1.0 x 10(-3) M DXM hydrobromide in pure as well as in dosage forms by direct potentiometry and standard addition methods. Determination of 5.0 x 10(-4) M DXM using the standard addition method and a sensor based on phosphomolybdate and dioctylphthalate shows an average recovery of 99.8% and a relative standard deviation (RSD) of 0.4%.
authors.affiliation: Narcotic Department, National Center for Social and Criminal Research, P. O. Zamalek Post, 11561, Cairo, Egypt. emanhasab@gmail.com
authors.forename: Eman H
authors.initials: EH
authors.lastname: El-Naby
mesh_terms: D003915:Dextromethorphan / Q000032:analysis*; D017736:Ion-Selective Electrodes; D053610:Opiate Alkaloids; D004364:Pharmaceutical Preparations / Q000737:chemistry; D011143:Polyvinyl Chloride; D011199:Potentiometry; D015203:Reproducibility of Results
chemical_list: D053610:Opiate Alkaloids; D004364:Pharmaceutical Preparations; D003915:Dextromethorphan; D011143:Polyvinyl Chloride