Innovative solutions for enhanced illicit drugs profiling using comprehensive two-dimensional gas chromatography and mass spectrometry technologies

This work presents the validation study of comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC×GC-TOFMS) method performance in analysis of the key WADA anabolic agents in doping control. The relative abundance ratio, retention time, identification and other method performance criteria have been tested in the GC×GC format to confirm if they comply with those set by WADA. Furthermore, tens of other components were identified with an average similarity of >920 (on the 0–999 scale), including 10 other endogenous sterols and full mass spectra of 5,000+ compounds were retained. The testosterone/epitestosterone ratio was obtained from the same run. A new dimension in doping analysis has been implemented by addressing separation improvement. Instead of increasing the method sensitivity that is accompanied by making the detector increasingly ‘blind’ to the matrix (as represented by selected ion monitoring mode, high-resolution mass spectrometry, tandem MS), the method capabilities have been improved by adding a new ‘separation’ dimension, while retaining full mass spectral scan information. Apart from the requirement for the mass spectral domain that a minimum of three diagnostic ions with relative abundance of five percent or higher in the MS spectra, all other WADA criteria are satisfied by GC×GC operation. The minimum of three diagnostic ions arises from the need to add some degree of specificity to the acquired mass spectrometry data; however, under the proposed full MS scan method, the high MS similarity to the reference compounds offers more than the required three diagnostic ions for an unambiguous identification. This should be viewed as an extension of the present criteria to a full scan MS method.