Development Of New Analytical Methods For Steroid Profiling For Doping Purposes

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dc.contributor.authorAbdul Manaf, Normaliza
dc.date.accessioned2019-04-04T06:43:16Z
dc.date.available2019-04-04T06:43:16Z
dc.date.issued2018-07
dc.description.abstractThe steroid profile compounds namely testosterone (T), epitestosterone (E), androsterone (A), etiocholanolone (Etio), 5alpha-androstane-3alpha,17beta-diol (5αAdiol), 5beta-androstane-3alpha,17beta-diol (5βAdiol) and the ratio of T to E (T/E)) has been determined in urine of male volunteers who consumed Tongkat Ali (TA) supplement using the solid phase extraction (SPE) and liquid-liquid extraction (LLE) method. From 47 samples, 11 samples violated the World Anti-Doping Agency (WADA) guidelines and confirmation by gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) showed 5 samples were consistent with the exogenous origin (Δδ13C > 3‰). Two microextraction methods, i.e., vortexassisted liquid-liquid microextraction (VALLME) and micro-solid phase extraction (μ-SPE) followed by LC-MS/MS were developed. Hypersil Gold C18 column (50 mm × 2.1 mm, 1.9 μm) with gradient elution resulted in baseline separation for compounds in about 8 min. The monitored ions are m/z 289.4 > 97.3 for T and E, m/z 273.4 > 255.3 for A and Etio and m/z 275.4 > 257.3 for 5αAdiol and 5βAdiol using electron spray ionization in the positive polarity mode. The optimum extraction conditions for 5 mL sample using the VALLME were: extraction solvent, 1- pentanol; volume of extractant, 150 μL; vortex time, 40 s; centrifuge speed and time, 1000 rpm for 1 min with no salt addition needed for the extraction. The optimum extraction conditions for 3 mL sample using the μ-SPE were: extraction solvent, acetonitrile; volume of extractant, 300 μL; extraction time, 30 min and desorption time, 20 min for the extraction. The VALLME-LC-MS/MS and μ-SPE-LC-MS/MS methods meet WADA requirements in terms of sensitivity, limit of detection, reproducibility, linearity and robustness. Furthermore, these alternative techniques were simple, rapid and environmentally friendly as markedly reduced amounts of solvents were involved.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/7937
dc.language.isoenen_US
dc.publisherUniversiti Sains Malaysiaen_US
dc.subjectDevelopment of new analytical methodsen_US
dc.subjectsteroid profiling for doping purposesen_US
dc.titleDevelopment Of New Analytical Methods For Steroid Profiling For Doping Purposesen_US
dc.typeThesisen_US
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