title: Analysis of corticosteroids in equine urine by liquid chromatography-mass spectrometry.
abstract: A liquid chromatography-mass spectrometry (LC-MS) method for the analysis of corticosteroids in equine urine was developed. Corticosteroid conjugates were hydrolysed with beta-glucuronidase; free and enzyme-released corticosteroids were then extracted from the samples with ethyl acetate followed by a base wash. The isolated corticosteroids were detected by LC-MS and confirmed by LC-MS-MS in the positive atmospheric pressure chemical ionisation mode. Twenty-three corticosteroids (comprising hydrocortisone, deoxycorticosterone and 21 synthetic corticosteroids), each at 5 ng/ml in urine, could easily be analysed in 10 min.
authors.affiliation: Racing Laboratory, The Hong Kong Jockey Club, Shatin Racecourse, NT.
authors.forename: P W
authors.initials: PW
authors.lastname: Tang
authors.forename: W C
authors.initials: WC
authors.lastname: Law
authors.forename: T S
authors.initials: TS
authors.lastname: Wan
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000652:urine*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000652:urine*; D002853:Chromatography, Liquid / Q000379:methods*; D003907:Dexamethasone / Q000008:administration & dosage / Q000652:urine; D005966:Glucuronidase; D006736:Horses / Q000652:urine*; D006854:Hydrocortisone / Q000652:urine; D013058:Mass Spectrometry; D008775:Methylprednisolone / Q000008:administration & dosage / Q000652:urine; D015203:Reproducibility of Results; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000652:urine
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D003907:Dexamethasone; D005966:Glucuronidase; D014222:Triamcinolone Acetonide; D006854:Hydrocortisone; D008775:Methylprednisolone