Simultaneous determination of polyether ionophores, macrolides and lincosamides in hen eggs by liquid chromatography-electrospray ionization tandem mass spectrometry using a simple solvent extraction.
A liquid chromatography-electrospray ionization tandem mass spectrometric (LC-ESI-MS/MS) method was developed and validated for the determination of residues of 6 polyether ionophores (lasalocid, maduramicin, monensin, narasin, salinomycin, semduramicin), 3 macrolides (erythromycin, tylosin, clarithromycin) and 1 lincosamide (lincomycin) in eggs. Nigericin was used as qualitative internal standard. Samples were deproteinizated/extracted with acetonitrile without pH adjustments. Aliquots of the extracts were evaporated and reconstituted for injection in the instrument operated in positive multiple reaction monitoring (MRM) mode. The stability of the antibiotics and the intensity of the formed ions were considered in order to select a suitable solvent for the reconstitution of the obtained dry extracts. No clean-up steps were required and matrix effects were controlled by sample dilution, selection of appropriate chromatographic conditions and reduced injection volume. Good within-laboratory reproducibility was obtained, with relative standard deviations (RSD(R)) from 4.0 (semduramicin at 5 μgkg(-1)) to 18.6 (erythromycin at 25 μgkg(-1)) for the ionophores and macrolides. Lincomycin showed the least precise results, with a maximum RSD(R) of 20.2% at 75 μgkg(-1)). Satisfactory decision limits (CCα) and detection capabilities (CCβ) were also attained. Method limits of detection (LODs) from 0.04 (salinomycin) to 1.6 μgkg(-1) (lincomycin) were achieved. Method limits of quantification (LOQs) were from 0.14 to 5.3 μgkg(-1) for the same drugs, respectively. All the LOQs, except that obtained for maduramicin were remarkably below the lowest validation level. The proposed method is suitable for routine application in commercial egg samples.
National Institute for Quality Control in Health/Oswaldo Cruz Foundation (INCQS/FIOCRUZ), Av. Brasil 4365, Rio de Janeiro, RJ, Brazil. bernardete.spisso@incqs.fiocruz.br
Bernardete Ferraz
BF
Spisso
Rosana Gomes
RG
Ferreira
Mararlene Ulberg
MU
Pereira
Mychelle Alves
MA
Monteiro
Tatiana Ávila
TÁ
Cruz
Rafaela Pinto
RP
da Costa
Adélia Mara Belém
AM
Lima
Armi Wanderley
AW
da Nóbrega
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002138:Calibration; D002645:Chickens; D002853:Chromatography, Liquid / Q000379:methods; D004531:Eggs / Q000032:analysis*; D007476:Ionophores / Q000032:analysis*; D057230:Limit of Detection; D055231:Lincosamides / Q000032:analysis*; D018942:Macrolides / Q000032:analysis*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000900:Anti-Bacterial Agents; D007476:Ionophores; D055231:Lincosamides; D018942:Macrolides