title: Estimation of thermodynamic acidity constants of some penicillinase-resistant penicillins.
abstract: In this work, thermodynamic acidity constants (pssKa) of methicillin, oxacillin, nafcillin, cloxacilin, dicloxacillin were determined with reverse phase liquid chromatographic method (RPLC) by taking into account the effect of the activity coefficients in hydro-organic water-acetonitrile binary mixtures. From these values, thermodynamic aqueous acidity constants of these drugs were calculated by different approaches. The linear relationships established between retention factors of the species and the polarity parameter of the mobile phase (ET(N)) was proved to predict accurately retention in LC as a function of the acetonitrile content (38%, 40% and 42%, v/v).
authors.affiliation: Department of Chemistry, Faculty of Science and Literature, Süleyman Demirel University, 32260 Isparta, Turkey. Electronic address: ebrucubuk@sdu.edu.tr.
authors.forename: Ebru Çubuk
authors.initials: EÇ
authors.lastname: Demiralay
authors.affiliation: Department of Chemistry, Faculty of Science and Literature, Süleyman Demirel University, 32260 Isparta, Turkey.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Üstün
authors.affiliation: Department of Chemistry, Faculty of Science and Literature, Süleyman Demirel University, 32260 Isparta, Turkey.
authors.forename: Y Doğan
authors.initials: YD
authors.lastname: Daldal
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D000143:Acids / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D006863:Hydrogen-Ion Concentration; D010405:Penicillinase / Q000737:chemistry*; D010406:Penicillins / Q000737:chemistry*; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D000143:Acids; D010406:Penicillins; D014867:Water; D010405:Penicillinase; C032159:acetonitrile
keywords: Activity coefficients; Polarity parameter; Thermodynamic acidity constants; Water–acetonitrile binary mixture