title: Liquid chromatography-electrospray ionization-mass spectrometry method in multiple reaction monitoring mode to determine 17alpha-ethynylestradiol residues in cattle hair without previous digestion.
abstract: A liquid chromatography-mass spectrometric (LC-MS/MS) method has been developed for determination of ethynylestradiol residues in cattle hair. Hair samples were pulverized with a cryogenic mill followed by a simple extraction with acetonitrile. A dansyl derivatization procedure to improve ethynylestradiol detection was used before the LC-MS/MS analysis in multiple reaction monitoring (MRM) mode using alpha-estradiol as an internal standard. The method was validated following the latest EU guidelines using blank hair samples spiked at 2 ng g(-1). The detection capability (CCbeta) was less than 2 ng g(-1), and the decision limit (CCalpha) was 1 ng g(-1). Incurred samples obtained 56 days after cow treatment with ethynylestradiol were analyzed, and the presence of ethynylestradiol in the hair was confirmed in all cases.
authors.affiliation: Laboratorio de Higiene, Inspección y Control de Alimentos, Area de Nutrición y Bromatología, Universidad de Santiago de Compostela, 27002 Lugo, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Pedreira
authors.forename: M
authors.initials: M
authors.lastname: Lolo
authors.forename: B I
authors.initials: BI
authors.lastname: Vázquez
authors.forename: C M
authors.initials: CM
authors.lastname: Franco
authors.forename: A
authors.initials: A
authors.lastname: Cepeda
authors.forename: C
authors.initials: C
authors.lastname: Fente
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues; D004997:Ethinyl Estradiol / Q000032:analysis*; D006197:Hair / Q000737:chemistry*; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D004997:Ethinyl Estradiol