Comprehensive two-dimensional gas chromatography improves separation and identification of anabolic agents in doping control

The application of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS) for the analysis of six anabolic agents (AAs) in doping control is investigated in this work. A non-polar-polar column configuration with 0.2 mu m film thickness (d(f)) second dimension (D-2) column was employed, offering much better spread of the components on D-2 when compared to the alternative 0.1 mu m d(r) D-2 column. The proposed method was tested on the key AA that the World Anti-Doping Agency (WADA) had listed at the low ngmL(-1) levels (clenbuterol, 19-norandrosterone, epimethendiol, 17 alpha-methyl-5 alpha-androstane-3 alpha, 17 beta-diol, 17 alpha-methyl-5 beta-androstane-3 alpha, 17 beta-diol and 3 -OH-stanozolol). The compounds were spiked in a blank urine extract obtained by solid-phase extraction, hydrolysis and liquid-liquid extraction; prior to analysis they were converted to the corresponding trimethylsilyl (TMS) derivatives.