Mass Spectrometry in doping control analysis

Mass spectrometry has become the most frequently employed technique in doping control analysis to identify prohibited compounds ever since their use has been banned by international federations. In combination with gas or liquid chromatography and various ionization methods such as electron or chemical ionization, electrospray, atmospheric pressure chemical ionization, atmospheric pressure photo ionization or matrix-assisted laser desorption ionization, numerous applications have been established enabling the sensitive and selective detection of prohibited drugs in matrices such as urine, blood, and hair. The classes of investigated compounds include low molecular weight drugs such as anabolic steroids, diuretics, beta(2)-agonists and beta-receptor blocking agents, and others as well as high molecular weight therapeutics, for instance plasma volume expanders based on polysaccharide structures (e.g. hydroxyethyl starch and dextran), hemoglobin-based oxygen therapeutics (e.g. Hemopure), or synthetic insulins. Assays for their identification are commonly based on extractive purification, chemical or enzymatic treatment (i.e. derivatization or degradation) followed by chromatographic and mass spectrometric analysis employing various modern analyzers such as quadrupole, ion trap, triple-quadrupole and magnetic-sector mass spectrometers allowing the sensitive and unambiguous qualitative as well as quantitative determination of xenobiotics in elite athletes' doping control samples. Moreover, the administration of drugs naturally occurring in human beings, for instance testosterone, is uncovered by carbon isotope ratio mass spectrometry that enables the differentiation between endogenous and exogenous sources. The comparison of delta-values obtained from endogenously produced steroids independent from testosterone and its metabolism with urinary testosterone and its metabolic products allow the determination of surreptitious applications.