HPLC-integrated solid-phase extraction with photochemical post-column derivatization for the determination of oxacillin, cloxacillin and dicloxacillin in raw milk

Simultaneous Determination of Five β-Lactam Antibiotics in Bovine Milk Using Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry

“…The determination of β-lactam antibiotics at trace levels in fresh milk requires a sensitive analytical method that in particular addresses the impact of sample preparation and the analytical step on the stability of the analytes (e.g., pH, organic solvents). ,, This may be the reason some multiresidue methods described in the literature differ significantly in sample preparation, while the determinative step is usually based on reversed-phase liquid chromatography (LC) coupled with UV detection. ,− Furthermore, many of the methods described are tedious, requiring a derivatization step and/or use an acidification step during sample preparation which is critical with regard to analyte stability.…”