Year: 2018
Type: dissertation
Abstract: Anabolic-androgenic steroids (AAS) are synthetic compounds that are structurally related to testosterone. AAS are an important class of drugs that are commonly abused in sport and are classified as prohibited substances according to the World Anti-Doping Agency (WADA). AAS are metabolized extensively in the human body and excreted to urine mostly as glucuronides or sulphates. These conjugated compounds are present in human specimens in low concentrations and for a limited period. Sensitive and specific analytical methods are thus highly important to be able to detect these compounds for an extended time period in athletes. These compounds are usually analyzed from biological matrixes after cleavage of the glucuronide or sulfonate moiety. Direct analysis of intact conjugated steroid metabolites is an attractive option that involves more straightforward sample preparation. Nonetheless, the commercial availability of the conjugated reference material is limited. The first aim of this study was to produce glucuronide-conjugated metabolites of AAS to be used in the development of methods for doping control. Glucuronide-conjugated metabolites of anabolic androgenic steroids were produced by in vitro enzyme-assisted synthesis. The method offers a simple and stereospecific procedure of producing small amounts of reference material, which are needed in the development and application of analytical methods for AAS metabolites. Secondly, these AAS glucuronides were utilized in the development of a liquid chromatography – mass spectrometry (LC-MS) method for detection of glucuronide-conjugated AAS metabolites in human urine. Novel method was validated, and the robustness and transferability of the developed method was studied in an interlaboratory comparison among seven laboratories. The developed method offers simpler and a more straightforward as well as sensitive approach to the analysis of exogenous steroids, without a hydrolysis process and time-consuming sample preparation. Another approach for a more sensitive and specific method for analysis of anabolic steroids from urine, was to combine gas chromatography (GC) featuring good resolving power to softer ionization in atmospheric pressure (API). A microchip-based miniaturized heated nebulizer provides easy interfacing for GC-API-MS with high ionization efficiency. Two sensitive and selective gas chromatography - microchip atmospheric pressure photoionization - tandem mass spectrometry (GC-µAPPI-MS/MS) methods were developed, validated and successfully applied to the analysis of anabolic steroids in authentic excretion urine samples. These methods offer valuable tools for anti-doping laboratories where new analytical strategies are needed to be able to detect an increasing number of prohibited compounds with various physico-chemical properties.
Source: Työväentutkimus Vuosikirja
Author: Laura Hintikka
Institution: University of Helsinki
Language: English
Topic: Doping in Sports
Subfield: Sociology and Political Science
Field: Social Sciences
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W2914032780