title: Aminoglycoside analysis in food of animal origin with a zwitterionic stationary phase and liquid chromatography-tandem mass spectrometry.
abstract: In this study, fourteen highly polar aminoglycoside (AGs) antibiotics were selected. Various stationary phases were tested, including Obelisc R, ZIC-HILIC, BEH amide and aminopropyl. The nature of the stationary phase, mobile phase (water or buffer solutions and acetonitrile), pH (percentage of formic acid), gradient conditions and injection solvents were systematically studied as relevant parameters for tuning retention selectivity and detectability of AGs in liquid chromatography electrospray tandem mass spectrometry (LC-(ESI)-MS/MS). Only the two zwitterionic phases (Obelisc R and ZIC-HILIC) achieved a proper chromatographic separation considering interferences due to the crosstalk effect in low resolution mass spectrometers. The water/acetonitrile mobile phase containing 1% formic acid used with Obelisc R provided more sensitivity than the highly concentrated buffered mobile phases required for ZIC-HILIC. A solid phase extraction (SPE) clean-up procedure with polymeric weak cation exchange (WCX) cartridges was optimized for honey, milk and liver samples. Different brands of cartridges and elution solvents were tested, and the Taurus WCX offered the best recovery rate with a buffer elution at pH 3. The final optimized method was validated in these matrices according to Decision 2002/657/EC. A monitoring campaign for sixty honey, milk and liver samples was carried out at the Food Authority Control in Geneva. The concentration of dihydrostreptomycin (DSTP) found in one ovine liver exceeded the established maximum residue levels (MRLs) within the European and Swiss legislations but it was compliant taking into account the validation data.
authors.affiliation: Official Food Authority Control and Veterinary Affairs (SCAV), Quai Ernest-Ansermet 22, 1211 Geneva 4, Switzerland; School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, Boulevard d'Yvoy 20, 1211 Geneva 4, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Díez
authors.affiliation: School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, Boulevard d'Yvoy 20, 1211 Geneva 4, Switzerland.
authors.forename: Davy
authors.initials: D
authors.lastname: Guillarme
authors.affiliation: Official Food Authority Control and Veterinary Affairs (SCAV), Quai Ernest-Ansermet 22, 1211 Geneva 4, Switzerland.
authors.forename: Aline
authors.initials: A
authors.lastname: Staub Spörri
authors.affiliation: Official Food Authority Control and Veterinary Affairs (SCAV), Quai Ernest-Ansermet 22, 1211 Geneva 4, Switzerland.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cognard
authors.affiliation: Official Food Authority Control and Veterinary Affairs (SCAV), Quai Ernest-Ansermet 22, 1211 Geneva 4, Switzerland.
authors.forename: Didier
authors.initials: D
authors.lastname: Ortelli
authors.affiliation: Official Food Authority Control and Veterinary Affairs (SCAV), Quai Ernest-Ansermet 22, 1211 Geneva 4, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Edder
authors.affiliation: School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, Boulevard d'Yvoy 20, 1211 Geneva 4, Switzerland. Electronic address: serge.rudaz@unige.ch.
authors.forename: Serge
authors.initials: S
authors.lastname: Rudaz
mesh_terms: D000617:Aminoglycosides / Q000032:analysis*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents
keywords: Aminoglycosides; Honey; Liver; Milk; Zwitterionic