Doping control screening based on the enhanced resolution of comprehensive two-dimensional (2D) gas chromatography hyphenated to time of flight mass spectrometer was investigated. The identification of anabolic agents (clenbuterol, norandrosterone, epimetendiol, two methyltestosterone metabolites and 3'-hydroxystanozolol) contained in a spiked urine sample (2ng/ml) was demonstrated. Special emphasis was given to 3'-hydroxystanozolol, mainly considering the difficulty in its detection. In contrast to conventional GC-MS approaches that must use single-ion monitoring, the GC x GC-TOFMS method enabled the identification of that metabolite through the deconvolution of the full mass spectrum and also resolved the co-eluted peaks of 3'-hydroxystanozolol and an endogenous component.