title: Determination of tylosins A, B, C and D in bee larvae by liquid chromatography coupled to ion trap-tandem mass spectrometry.
abstract: A LC-MS/MS method has been developed to simultaneously quantify tylosins A, B, C and D in bee larvae, compounds currently used to treat one of the most lethal diseases affecting honey bees around the world, American Foulbrood (AFB). The influence of different aqueous media, temperature and light exposure on the stability of these four compounds was studied. The analytes were extracted from bee larvae with methanol and chromatographic separation was achieved on a Luna C(18) (150 × 4.6 mm i.d.) using a ternary gradient composed of a diluted formic acid, methanol and acetonitrile mobile phase. To facilitate sampling, bee larvae were initially dried at 60°C for 4h and afterwards, they were diluted to avoid problems of pressure. MSD-Ion Trap detection was employed with electrospray ionization (ESI). The calibration curves were linear over a wide range of concentrations and the method was validated as sensitive, precise and accurate within the limits of quantification (LOQ, 1.4-4.0 ng/g). The validated method was successfully employed to study bee larvae in field tests of bee hives treated with two formulations containing tylosin. In both cases it was evident that the minimal inhibitory concentration (MIC) had been reached.
authors.affiliation: IU CINQUIMA, Analytical Chemistry, Faculty of Sciences, University of Valladolid, Valladolid, Spain. jose.bernal@qa.uva.es
authors.forename: J
authors.initials: J
authors.lastname: Bernal
authors.forename: Ma T
authors.initials: MT
authors.lastname: Martín
authors.forename: L
authors.initials: L
authors.lastname: Toribio
authors.forename: R
authors.initials: R
authors.lastname: Martín-Hernández
authors.forename: M
authors.initials: M
authors.lastname: Higes
authors.forename: J L
authors.initials: JL
authors.lastname: Bernal
authors.forename: M J
authors.initials: MJ
authors.lastname: Nozal
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis; D056630:Beekeeping; D001516:Bees / Q000737:chemistry* / Q000382:microbiology; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D007814:Larva / Q000737:chemistry; D016018:Least-Squares Analysis; D008027:Light; D056507:Paenibacillus / Q000302:isolation & purification; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013696:Temperature; D015645:Tylosin / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D015645:Tylosin