RESUMO
A reversed phase ion-pair liquid chromatographic method using a base deactivated column and pulsed electrochemical detection on a gold electrode is described. It allows the separation of a mixture of spectinomycin sulfate, lincomycin hydrochloride and their related substances. A step gradient was necessary to obtain a good separation together with a reasonable analysis time of 40 min. The mobile phases consisted of an aqueous solution of 3.3 or 0.55 g/l pentanesulfonic acid, 10 mM acetic acid and 20 ml/l tetrahydrofuran. Both mobile phases were adjusted to pH 4.0 with diluted sodium hydroxide. The influence of the different chromatographic parameters on the separation was investigated. Two commercial samples were analyzed using the described method. In total 12 components could be separated.
Assuntos
Antibacterianos/análise , Cromatografia Líquida/métodos , Eletroquímica/métodos , Lincomicina/análise , Espectinomicina/análise , Química Farmacêutica , Concentração de Íons de HidrogênioRESUMO
The determination of tobramycin by liquid chromatography using a column packed with poly(styrene-divinylbenzene) and pulsed electrochemical detection on a gold electrode is described. The mobile phase consisted of an aqueous solution containing 52 g/l of sodium sulfate, 1.5 g/l of sodium octanesulfonate and 50 ml/l of a 0.2 M phosphate buffer pH 3.0. The total time of analysis was not more than 30 min. The effects of the different chromatographic parameters on the separation were also investigated. When a number of commercial samples of tobramycin was analyzed using this method, nine different components were separated, five of which are of unknown identity.
Assuntos
Tobramicina/análise , Antibacterianos/análise , Cromatografia Líquida , Eletroquímica , Indicadores e Reagentes , Poliestirenos , Padrões de Referência , Soluções , Compostos de VinilaRESUMO
Overpressured layer chromatography was combined with the highly sensitive and rapid digital autoradiography (DAR) and mass spectrometry to separate, detect, and identify 3H- and 14C-labeled deramciclane metabolites in different biological matrixes. Several minor and major metabolites were separated from plasma and urine samples. The radioactive metabolites localized by DAR were scraped from the thin-layer chromatographic plate and transferred to a mass spectrometer for structure identification. Several metabolites were isolated and characterized, including hydroxy-N-desmethyl deramciclane, which is described in detail. The combination of techniques is efficient and has good sensitivity: about 2 micrograms metabolite from a biological matrix was isolated and identified this way.
