Spectroscopic and Conductometric Characterization of the Ion-Pairs Constituted by Oxyphenonium Bromide in Aqueous Solutions

In this study, spectroscopic and conductometric investigations of the interactions between oxyphenonium bromide (OXBr) and two dyes; chromotrope 2R (C2R) and ammonium reineckate (AMRT) are reported. The solubility product constant as well as other parameters related to the process of precipitating OXBr is premeditated operating the conductometric procedure. Moreover, contemporary approaches towards equivalence point localization have been pursued and compared. In this itinerary, the numerical differential conductivity methods were objective and systematic. However, Boltzmann sigmoid fitting model was more adequate for data analysis with less errors compared to the conventional and the differential methods. A molar ratio of (1:1) (OXBr:reagent) complexes in aqueous solutions have been determined conductometrically.The described procedures allowed the investigation of OXBr within the range of 3-15 mg using both reagents. Moreover, the obtained precipitate has been spectroscopically characterized using IR and 1H-NMR. The proposed conductometric method was applied successively to pharmaceutical formulations containing OXBr and the results obtained were favorably compared with those obtained using the reference method.