Abstract des Autors

A hydrophilic interaction liquid chromatography–tandem mass spectrometry method (HILIC–MS/MS) was developed for the simultaneous determination of 28 amphetamine‐type stimulants (ATSs) in equine plasma for doping control analysis. In this method, stimulants were recovered from equine plasma by liquid–liquid extraction (LLE) at pH 9.5 using methyl tert ‐butyl ether and detected on a Thermo Finnigan triple quadrupole mass spectrometer operating in positive‐ion mode electrospray ionization. All stimulants were eluted within 7 minutes and baseline separation was achieved for isomeric and isobaric compounds using HILIC chromatography. Extraction efficiency was greater than 80% and matrix effect was acceptable for most stimulants. The limit of detection (LOD) was in the range of 10–50 pg/mL and the lower limit of quantification (LLOQ) was in the range of 50–100 pg/mL. Quadratic regression was employed for quantification and the dynamic range of quantification was 50–10000 pg/mL. Confirmatory analysis criteria were established using product ion ratios and retention time. The limit of confirmation (LOC) was in the range of 20–100 pg/mL. Stability study results indicated that some stimulants were unstable in equine plasma at room temperature and 4°C. However, all the stimulants studied were stable at −20°C and − 80°C for the 6 month study period.