Comprehensive plasma‐screening for known and unknown substances in doping controls

Abstract

Occasionally, doping analysis has been recognized as a competitive challenge between cheating sportsmen and the analytical capabilities of testing laboratories. Both have made immense progress during the last decades, but obviously the athletes have the questionable benefit of frequently being able to switch to new, unknown and untested compounds to enhance their performance. Thus, as analytical counteraction and for effective drug testing, a complementary approach to classical targeted methods is required in order to implement a comprehensive screening procedure for known and unknown xenobiotics. The present study provides a new analytical strategy to circumvent the targeted character of classical doping controls without losing the required sensitivity and specificity. Using 50 microL of plasma only, the method potentially identifies illicit drugs in low ng/mL concentrations. Plasma provides the biological fluid with the circulating, unmodified xenobiotics; thus the identification of unknown compounds is facilitated. After a simple protein precipitation, liquid chromatographic separation and subsequent detection by means of high resolution/high accuracy orbitrap mass spectrometry, the procedure enables the determination of numerous compounds from different classes prohibited by the World Anti-Doping Agency (WADA). A new hyphenated mass spectrometry technology was employed without precursor ion selection for higher collision energy dissociation (HCD) fragmentation experiments. Thus the mass spectra contained all the desired information to identify unknown substances retrospectively. The method was validated for 32 selected model compounds for qualitative purposes considering the parameters specificity, selectivity, limit of detection (<0.1-10 ng/mL), precision (9-28%), robustness, linearity, ion suppression and recovery (80-112%). In addition to the identification of unknown compounds, the plasma samples were simultaneously screened for known prohibited targets.

Quantitative structure–retention relationships models for prediction of high performance liquid chromatography retention time of small molecules: Endogenous metabolites and banned compounds

“…For untargeted metabolome analysis, confident identification is the bottleneck due to: (1) the large number of detected metabolites present in complex matrices, (2) limited access to reference standards, (3) time consumption and (4) uncertainty of the results until fragmentation patterns are known. Unfortunately, current methods for analysis of doping samples, in spite of their high sensitivity and specificity, are still unable to determine newly created illegal substances, allowing for the secret use of these new synthesized drugs [8]. Furthermore, at the present time it is commonly accepted, that the fully comprehensive metabolomics/doping approach is not possible in a single platform.…”

Current status and bioanalytical challenges in the detection of unknown anabolic androgenic steroids in doping control analysis

“…Hence, the development of full acquisition methods based on HR instru ments is a promising alternative, not only for the open detection of AAS but also for the compre hensive target screening in doping control ana lysis (Table 2) [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66]. Their modus operandi is the acquisition of the fullscan raw data and, therefore, the detection of all compounds ion ized by the source.…”

Pharmacokinetics and in vitro efficacy of salicylic acid after oral administration of acetylsalicylic acid in horses

“…For plasma samples, a direct injection method published by Thomas et al [12] was modified. To 500 μL Milli-Q-water and 1 μg of the internal standard D4-SA 500 μl plasma were added.…”