title: Feasibility of a liquid-phase microextraction sample clean-up and liquid chromatographic/mass spectrometric screening method for selected anabolic steroid glucuronides in biological samples.
abstract: Anabolic androgenic steroids (AAS) are metabolized extensively in the human body, resulting mainly in the formation of glucuronide conjugates. Current detection methods for AAS are based on gas chromatographic/mass spectrometric (GC/MS) analysis of the hydrolyzed steroid aglycones. These analyses require laborious sample preparation steps and are therefore time consuming. Our interest was to develop a rapid and straightforward method for intact steroid glucuronides in biological samples, using liquid-phase microextraction (LPME) sample clean-up and concentration method combined with liquid chromatographic/tandem mass spectrometric (LC/MS/MS) analysis. The applicability of LPME was optimized for 13 steroid glucuronides, and compared with conventional liquid-liquid extraction (LLE) and solid-phase extraction (SPE) procedures. An LC/MS/MS method was developed for the quantitative detection of AAS glucuronides, using a deuterium-labeled steroid glucuronide as the internal standard. LPME, owing to its high specificity, was shown to be better suited than conventional LLE and SPE for the clean-up of urinary AAS glucuronides. The LPME/LC/MS/MS method was fast and reliable, offering acceptable reproducibility and linearity with detection limits in the range 2-20 ng ml(-1) for most of the selected AAS glucuronides. The method was successfully applied to in vitro metabolic studies, and also tested with an authentic forensic urine sample. For a urine matrix the method still has some unsolved problems with specificity, which should be overcome before the method can be reliably used for doping analysis, but still offering additional and complementary data for current GC/MS analyses.
authors.affiliation: Division of Pharmaceutical Chemistry, Department of Pharmacy, P.O. Box 56, 00014 University of Helsinki, Finland.
authors.forename: Tiia
authors.initials: T
authors.lastname: Kuuranne
authors.forename: Tapio
authors.initials: T
authors.lastname: Kotiaho
authors.forename: Stig
authors.initials: S
authors.lastname: Pedersen-Bjergaard
authors.forename: Knut
authors.initials: K
authors.lastname: Einar Rasmussen
authors.forename: Antti
authors.initials: A
authors.lastname: Leinonen
authors.forename: Steven
authors.initials: S
authors.lastname: Westwood
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
mesh_terms: D045930:Anabolic Agents / Q000737:chemistry* / Q000652:urine*; D002138:Calibration; D002853:Chromatography, Liquid; D005260:Female; D020719:Glucuronides / Q000737:chemistry* / Q000652:urine*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D045930:Anabolic Agents; D020719:Glucuronides