title: Determination of erythromycin and related substances in commercial samples using liquid chromatography/ion trap mass spectrometry.
abstract: A sensitive, precise and accurate quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the measurement of erythromycin A (EA) and related substances in commercial samples was developed and validated. The samples were chromatographed on a reversed-phase column with a polar endcapping and analyzed by ion trap tandem mass spectrometry in the multiple reaction monitoring (MRM) mode using positive electrospray ionization. The method showed high recovery (>or=98.82%), high sensitivity (lower limit of quantitation of 0.25 ng/mL for EA and less than 7.3 ng/mL for the related substances) and high precision (<or=0.52%) as well as excellent linearity (r(2)>or=0.991) with a run time of only 13 min. The method was successfully applied to the determination of EA and related substances in commercial samples. Moreover, using the advanced data-dependent acquisition capability of the ion trap software two new unexpected EA related substances could be detected and possible structures for these substances were postulated.
authors.affiliation: Institute of Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Deubel
authors.forename: A S
authors.initials: AS
authors.lastname: Fandiño
authors.forename: F
authors.initials: F
authors.lastname: Sörgel
authors.forename: U
authors.initials: U
authors.lastname: Holzgrabe
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004917:Erythromycin / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin