Development of a Standardized Microflow LC Gradient
to Enable Sensitive and Long-Term Detection of Synthetic Anabolic-Androgenic
Steroids for High-Throughput Doping Controls
Synthetic androgenic anabolic steroids
(AAS) are banned compounds
and considered as major threats by both racing and sports international
authorities. Hence, doping control laboratories are continually looking
into analytical improvements to increase their detection capabilities,
notably by means of emerging technologies. To enhance analytical performances
for the detection of synthetic AAS such as stanozolol, specific chromatographic
procedures have been developed using recent quaternary liquid chromatography
technology originally designed for high-throughput standardized proteomics
connected to mass spectrometry. Applying the newly designed elution
procedures described in this paper to the analyses of stanozolol and
its metabolites in complex matrixes revealed improved sensitivity
compared to previously described high-throughput methods. Indeed,
we report the consistent and reliable detection of 16β-hydroxy-stanozolol
down to 10 pg/mL in equine urine and being detectable up-to 3 months
after a microdosing administration. Furthermore, a five months long
elimination of stanozolol and its metabolites could be monitored on
horse mane sections after a single dose administration. Our work highlights
novel solutions to detect AAS with improved sensitivity. The application
of such developments constitutes new landmarks for doping control
laboratories and could be extended to other targeted compounds in
residue analysis, toxicology, and metabolomics. Based on this work,
the developed chromatographic method is now freely available within
the Evosep Plus program.