title: [A potentiometric method of quantitative analysis of rifampicin].
abstract: A potentiometric procedure for assay of rifampicin was developed. The procedure implies titration of rifampicin as a monofunctional acid by sodium hydroxide solution (0.1 mol/l) in 75 per cent aqueous methanol. The constant ionic strength of the solution is provided by addition of KCl until its concentration is 0.1 mol/l, the titrant concentration being 10 times higher than the antibiotic concentration in the solution. This provides a precise determination of the concentration ionization constant of the antibiotic as a monofunctional acid (pKa 7.33 +/- 0.01) and an insignificant dilution of the antibiotic solution during the titration promoting precise and reproducible results. The procedure error is 0.20 per cent. The variation coefficient is 0.27 per cent.
authors.forename: G D
authors.initials: GD
authors.lastname: Ovcharova
authors.forename: R N
authors.initials: RN
authors.lastname: Nacheva
authors.forename: D B
authors.initials: DB
authors.lastname: Dimitrova
mesh_terms: D006851:Hydrochloric Acid / Q000008:administration & dosage; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000008:administration & dosage; D009994:Osmolar Concentration; D011199:Potentiometry / Q000379:methods; D012293:Rifampin / Q000032:analysis*; D012965:Sodium Chloride / Q000008:administration & dosage; D012996:Solutions
chemical_list: D012996:Solutions; D012965:Sodium Chloride; D006851:Hydrochloric Acid; D012293:Rifampin; D000432:Methanol
vernacular_title: Potentsiometricheskiĭ metod kolichestvennogo opredeleniia rifampitsina.