title: Negative ion electrospray ionization tandem mass spectrometry in the structural characterization of penicillins.
abstract: The mass spectrometry (MS) behaviour of ten commercially available penicillins has been studied by means of electrospray and multiple-stage MS/MS experiments performed using an ion trap instrument. For all the examined compounds negative ions are produced under ESI conditions, with a yield two or three orders of magnitude higher than that observed for positive ions. MSn experiments indicate the occurrence of a fragmentation pathway related to the beta-lactam ring, different from that usually described for positive ions of these compounds, and provide structural information on both the beta-lactam ring and the side chains.
authors.affiliation: RIBBON S.r.l., Milano, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Rabbolini
authors.forename: E
authors.initials: E
authors.lastname: Verardo
authors.forename: M
authors.initials: M
authors.lastname: Da Col
authors.forename: A M
authors.initials: AM
authors.lastname: Gioacchini
authors.forename: P
authors.initials: P
authors.lastname: Traldi
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D013058:Mass Spectrometry; D010406:Penicillins / Q000737:chemistry*
chemical_list: D010406:Penicillins