Detection and characterization of a new metabolite of 17alpha-methyltestosteroneOscar J Pozo
DoCoLab, Ghent University, Department of Clinical Chemistry, Microbiology and Immunology, Zwijnaarde, Belgium
Drug Metab Dispos 37:2153-62. 2009
..6-Ene-epimethyltestosterone was found in all samples, showing its applicability in the detection of methyltestosterone misuse...
- Combination of liquid-chromatography tandem mass spectrometry in different scan modes with human and chimeric mouse urine for the study of steroid metabolism
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, Zwijnaarde, Belgium
Drug Test Anal 1:554-67. 2009
..The metabolic nature of the unreported metabolites was also confirmed. A global strategy for the detection of steroid metabolites combining both human and chimeric mouse urine is proposed...
- Steroid metabolism in chimeric mice with humanized liver
Leen Lootens
Department of Clinical Chemistry, Microbiology and Immunology, Doping control laboratory DoCoLab, Ghent University, Technologiepark 30, Zwijnaarde, Belgium
Drug Test Anal 1:531-7. 2009
..It is hoped that, in future, this promising chimeric mouse model might assist the discovery of new and possible longer detectable metabolites of (designer) steroids...
- uPA+/+-SCID mouse with humanized liver as a model for in vivo metabolism of exogenous steroids: methandienone as a case study
Leen Lootens
Doping Control Laboratory, Zwijnaarde, Belgium
Clin Chem 55:1783-93. 2009
..In this study we investigated whether uPA(+/+)-SCID mice carrying functional primary human hepatocytes in their liver would provide a suitable alternative small animal model for the investigation of human steroid metabolism in vivo...
- Detection and structural investigation of metabolites of stanozolol in human urine by liquid chromatography tandem mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Steroids 74:837-52. 2009
..Finally, a tentative structure for each detected metabolite has been proposed based on the product ion spectra measured with accurate masses using UPLC-QTOF MS...
- Comparison between triple quadrupole, time of flight and hybrid quadrupole time of flight analysers coupled to liquid chromatography for the detection of anabolic steroids in doping control analysis
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Anal Chim Acta 684:98-111. 2011
..Additionally, the intake of methandienone was confirmed by the post-target detection of a long-term metabolite...
Elucidation of urinary metabolites of fluoxymesterone by liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometryOscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
J Mass Spectrom 43:394-408. 2008
..The presence of these compounds has also been confirmed by the analysis of five other positive fluoxymesterone urine samples...
- Development and validation of a qualitative screening method for the detection of exogenous anabolic steroids in urine by liquid chromatography-tandem mass spectrometry
Oscar J Pozo
DoCoLab, Department of Clinical Chemistry, Microbiology and Immunology, University of Ghent, Technologiepark 30, 9052, Zwijnaarde, Belgium
Anal Bioanal Chem 389:1209-24. 2007
..Limits of detection between 1 and 10 ng/ml were obtained for most analytes which fulfil current requirements. The applicability of the method was shown by analysing positive samples...
- Collision-induced dissociation of 3-keto anabolic steroids and related compounds after electrospray ionization. Considerations for structural elucidation
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Rapid Commun Mass Spectrom 22:4009-24. 2008
..A correlation between the steroid structure and the product ions obtained has been postulated. The application of these correlations can be useful in the elucidation of feasible structures for unknown steroids and/or their metabolites...
- Presence of endogenous interferences in the urinary detection of selected anabolic steroids by liquid chromatography/electrospray tandem mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Rapid Commun Mass Spectrom 21:2785-96. 2007
..Using this approach, several endogenous interferences have been elucidated in this case study. The knowledge about the structures of these interferences has been found useful to circumvent their detection in the screening method for AS...
- Direct quantification of steroid glucuronides in human urine by liquid chromatography-electrospray tandem mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, Zwijnaarde, Belgium
J Chromatogr A 1183:108-18. 2008
..97. A slope close to 1 was obtained for all analytes except for AG possibly due to losses during the extraction process prior to GC-MS...
- Efficient approach for the comprehensive detection of unknown anabolic steroids and metabolites in human urine by liquid chromatography-electrospray-tandem mass spectrometry
Oscar J Pozo
DoCoLab, Gent University, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Anal Chem 80:1709-20. 2008
..Finally, the applicability of the developed approach for the analysis of dietary supplements was checked by the analysis of a prohormone where several impurities and/or degradation products were found...
- Quantification of testosterone undecanoate in human hair by liquid chromatography-tandem mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Zwijnaarde, Belgium
Biomed Chromatogr 23:873-80. 2009
..2 ng/g. The applicability of the method was checked by the analysis of three samples from patients using T-C11. A peak for the analyte was detected in all samples with concentrations between 0.4 and 8.4 ng/g...
- Ionization of anabolic steroids by adduct formation in liquid chromatography electrospray mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
J Mass Spectrom 42:497-516. 2007
..Despite the ionization limitations due to their chemical structure, most of tested anabolic steroids could be ionized using the adduct formation approach...
- Quantitative detection of inhaled salmeterol in human urine and relevance to doping control analysis
Koen Deventer
DoCoLab, Department of Clinical Chemistry, Microbiology and Immunology, UGent, Zwijnaarde, Gent, Belgium
Ther Drug Monit 33:627-31. 2011
..Analysis of 47 routine doping samples, declared to contain salmeterol during routine analysis, did not exhibit concentrations that could be considered originating from supratherapeutic doses...
- Development of a qualitative liquid chromatography/tandem mass spectrometric method for the detection of narcotics in urine relevant to doping analysis
Koen Deventer
Ghent University Ugent, Department of Clinical Chemistry, Microbiology and Immunology, Doping control laboratory DoCoLab, Technologiepark 30, B 9052 Zwijnaarde, Belgium
Rapid Commun Mass Spectrom 21:3015-23. 2007
..Finally, the described method was applied to the analysis of urine samples previously found to contain narcotics by our routine gas chromatography/mass spectrometry (GC/MS) method...
- Evaluation of different scan methods for the urinary detection of corticosteroid metabolites by liquid chromatography tandem mass spectrometry
Oscar J Pozo
DoCoLab, UGent, Department of Clinical Chemistry, Microbiology and Immunology, Technologiepark 30, B 9052 Zwijnaarde, Belgium
J Mass Spectrom 44:929-44. 2009
..A combination of the reported methods seems to be the approach of choice in order to have a global overview about the excreted corticosteroid metabolites...
