Toward the use of a molecularly imprinted polymer in doping analysis: selective preconcentration and analysis of testosterone and epitestosterone in human urine.

A molecularly imprinted polymer (MIP), templated with methyltestosterone, has been synthesized for the cleanup of hydrolyzed urine samples for subsequent testosterone (T) quantification by LC-MS/MS. A concentration of 2 ng/mL testosterone could be quantified after a single step extraction on the MIP. The limit of detection and quantification with the criteria of a signal-to-noise ratio of 3 and 5 were 0.3 and 2 ng/mL, respectively. These values meet the conditions set by the World Anti-Doping Agency for the minimum required performance limits for doping controls, between 2 and 10 ng/mL. Epitestosterone (E) was also separated on this polymer and could be detected at concentrations down to 0.3 ng/mL. The quantification of T and E gives access to the determination of the T/E ratio, essential in doping analysis. Hence, our polymers can offer a more specific extraction procedure, resulting in increased sensitivity with limits of detection 10 times lower than the ones achieved by the standard SPE C(18) sorbents employed in official testing laboratories.