Compilation of an ESI-MS Library of β-Lactam Antibiotics for Rapid Identification of Drugs

Structural characterization of product ions by electrospray ionization and quadrupole time-of-flight mass spectrometry to support regulatory analysis of veterinary drug residues in foods

“…These bicyclic structures follow a general MS/MS fragmentation pattern as indicated by dashed lines in Fig. , in agreement with a previously published scheme . When the cleavage occurs across the β‐lactam ring, the product ions obtained are labeled A1 and A2; and/or when the cleavage involves the β‐lactam and the heterocyclic ring, the product ion is labeled as B.…”

“…General fragmentation pathways proposed for the protonated form of (a) penicillin‐type antibiotics and (b) cephalosporins‐type antibiotics (redrawn based on literature).…”

Determination of flomoxef in human plasma by liquid chromatography/electrospray ionization tandem mass spectrometry

“…Figure shows spectra of product ions under optimized conditions. The most stable and intensive fragments were 199.1 m / z in positive‐ion registration mode and 144.9 m / z in negative‐ion registration mode The formation of these product ion peaks was consistent with previously reported data (Kobayashi et al ., ; Chong and Hu, ). Thus electrospray ionization in negative‐ion mode appeared to be the more relevant method for flomoxef detection, so it was used for the method development.…”

Detection of the iron complexes with hydrolysis products of cephalexin and cefradine upon high‐performance liquid chromatography/electrospray ionization mass spectrometry analysis

“…Electrospray ionization mass spectrometry, usually coupled with high‐performance liquid chromatography (HPLC/ESI‐MS), has been successfully applied to their analysis . However, there is little nuclear magnetic resonance (NMR) data reported concerning the products of their hydrolysis and, to the best of our knowledge, there is no ESI‐MS data reported concerning the products.…”