Results 121 to 130 of about 357 (143)
Accreditation and Quality Assurance, 2007 A high-accuracy exact-matching isotope dilution mass spectrometry (IDMS) method for 19-norandrosterone (19-NA) in human urine was developed at NMIA for the certification of a freeze-dried human urine reference material (CRM NMIA MX002). The method utilised GC/HRMS analysis following hydrolysis, solvent extraction, HPLC fractionation and derivatisation.
Lindsey G. Mackay +7 more
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Doping in sport: 3. Metabolic conversion of oral norethisterone to urinary 19-norandrosterone
Steroids, 2008 The detection of 19 norandrosterone (19-NA) in a competitor's urine sample is taken as prima facie evidence of administration of nandrolone or other 19-norsteroid but a potential problem is that administration of norethisterone, a progestogen used for menstrual disorders and for hormonal contraception, also results in the excretion of 19-NA that can ...
Christopher J. Walker +4 more
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Rapid Communications in Mass Spectrometry, 2001 Abstract In previous work (Le Bizec et al ., Rapid Commun. Mass Spectrom . 2000; 14: 1058), it was demonstrated that a boar meal intake could lead to possible false accusations of abuse of 17β‐nortestosterone in antidoping control. The
Katia De Wasch +4 more
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Rapid Communications in Mass Spectrometry, 2000 For the first time in the field of steroid residues in humans, demonstration of 19-norandrosterone (19-NA: 3alpha-hydroxy-5alpha-estran-17-one) and 19-noretiocholanolone (19-NE: 3alpha-hydroxy-5beta-estran-17-one) excretion in urine subsequent to boar consumption is reported.
Bruno Le Bizec +6 more
+7 more sources
Steroids, 2008 19-Norandrosterone (19-NA) as its glucuronide derivative is the target metabolite in anti-doping testing to reveal an abuse of nandrolone or nandrolone prohormone. To provide further evidence of a doping with these steroids, the sulfoconjugate form of 19-norandrosterone in human urine might be monitored as well.
Emmanuel Strahm +5 more
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Accreditation and Quality Assurance, 2007 Under the auspices of the Comite Consultatif pour la Quantite de Matiere (CCQM) a laboratory intercomparison, CCQM-P68, was co-ordinated by the National Measurement Institute of Australia (NMIA) in 2005 involving the analysis of the steroid 19-norandrosterone (19-NA) in human urine.
Lindsey G. Mackay +7 more
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Accreditation and Quality Assurance, 2007 The method used at LGC for analysis of “total” 19-norandrosterone (19-norandrosterone glucuronide plus “free” 19-norandrosterone) in urine for the Comite Consultatif pour la Quantite de Matiere Pilot Study (CCQM-P68) is described. The analytical method used was a modified version of the method developed at the National Measurement Institute of ...
Chris Mussell +3 more
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Drug Testing and Analysis, 2020 Abstract19‐Norandrosterone (19‐NA) is the main metabolite of nandrolone and/or its precursors, which can be found naturally in human urine in trace amount. Gas chromatography–combustion–isotope ratio mass spectrometry (GC–C–IRMS) confirmation procedure can be used to identify a potential exogenous origin of 19‐NA in urine sample.
Chao Wen +5 more
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Journal of Chromatography B: Biomedical Sciences and Applications, 1999 A GC-MS method, using deuterium-labelled 19-noretiocholanolone as internal standard and following an extensive LC purification prior to selected ion monitoring of the bis(trimethylsilyl) ethers at ion masses m/z 405, 419, 420 and 421, allowed the quantitation of subnanogram amounts of 19-norandrosterone present in 10-ml urine samples at m/z 405. Thirty
L. Dehennin, Yves Bonnaire, P. Plou
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Drug Testing and Analysis, 2015 We have studied whether the phase II metabolism of 19‐norandrosterone, the most representative metabolite of 19‐nortestosterone (nandrolone), can be altered in the presence of other drugs that are not presently included on the Prohibited List of the World Anti‐Doping Agency.
Amelia Palermo +5 more
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