title: Bioanalysis of erythromycin 2'-ethylsuccinate in plasma using phase-system switching continuous-flow fast atom bombardment liquid chromatography-mass spectrometry.
abstract: A specific method for the determination of erythromycin 2'-ethylsuccinate (EM-ES) in plasma is described. The method involves a liquid-liquid extraction procedure followed by the analysis of extracts using phase-system switching (PSS) continuous-flow fast atom bombardment (CF-FAB) liquid chromatography-mass spectrometry (LC-MS). In PSS EM-ES is enriched after analytical separation on a short trapping column, from which it is desorbed to the LC-MS interface. In this way, favourable mobile phases can be used for the LC separation and for the MS detection. Using the PSS approach a flow-rate reduction from 1.0 ml/min in the LC system to 15 microliters/min going into the mass spectrometer was achieved without splitting. The determination limit for EM-ES was 0.1 microgram/ml.
authors.affiliation: TNO CIVO-Institutes, Zeist, The Netherlands.
authors.forename: P S
authors.initials: PS
authors.lastname: Kokkonen
authors.forename: W M
authors.initials: WM
authors.lastname: Niessen
authors.forename: U R
authors.initials: UR
authors.lastname: Tjaden
authors.forename: J
authors.initials: J
authors.lastname: van der Greef
mesh_terms: D015643:Erythromycin Ethylsuccinate / Q000097:blood*; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D011355:Prodrugs / Q000032:analysis*
chemical_list: D011355:Prodrugs; D015643:Erythromycin Ethylsuccinate