title: Cryogenic grinding pre-treatment improves extraction efficiency of fluoroquinolones for HPLC-MS/MS determination in animal tissue.
abstract: An efficiency extraction of fluoroquinolones in chicken muscle was achieved by pulverizing it in a freezer mill before treatment with NaOH (10mM)/MeCN (1:1). The improvement of cryogenic grinding in the extraction was demonstrated for the same piece (whole leg) of four chickens treated with enrofloxacin in equal doses. A confirmatory method based on high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was used to analyze the extracts. The chromatographic separation was achieved in 5 min with a Synergi Fusion-RP 80A (50 x 2 mm, 4 microm) column filled with a hybrid polymer. The HPLC was coupled with a detector based in a quadrupole-linear ion trap Q-TRAP that allows a confirmatory detection according to the European legislation. The specificity of the method was assessed by testing a number of representative blank muscle samples (n = 10) to verify the absence of potential interfering compounds. The limits of detection and quantitation were 2 and 5 ng g(-1) of quinolones in muscle samples, respectively. The chromatographic method was demonstrated to be linear for the range studied (5-500 ng g(-1)) with the P value for lack-of-fit in the ANOVA table greater or equal to 0.10 (calibration coefficient 0.9998 and 0.9996 for ciprofloxacin and enrofloxacin, respectively). The mean intra-day relative standard deviation (RSD) (n = 6, c = 50 ng g(-1)) was 6%; inter-day assay gave a RSD of 12%. The extraction and clean-up were carried out in one step with very satisfactory recovery data (between 65 and 101%).
authors.affiliation: Laboratorio de Higiene, Inspección y Control de Alimentos, Area de Nutrición y Bromatología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Lolo
authors.forename: Sandra
authors.initials: S
authors.lastname: Pedreira
authors.forename: Beatriz I
authors.initials: BI
authors.lastname: Vázquez
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Franco
authors.forename: Alberto
authors.initials: A
authors.lastname: Cepeda
authors.forename: Cristina A
authors.initials: CA
authors.lastname: Fente
mesh_terms: D000818:Animals; D005591:Chemical Fractionation / Q000379:methods*; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015925:Cryopreservation / Q000379:methods*; D024841:Fluoroquinolones / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D018482:Muscle, Skeletal / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods; D046509:Tissue Culture Techniques / Q000379:methods*
chemical_list: D024841:Fluoroquinolones