title: Sensitive hydrophilic interaction liquid chromatography/tandem mass spectrometry method for rapid detection, quantification and confirmation of cathinone-derived designer drugs for doping control in equine plasma.
abstract: BACKGROUND
  Cathinone derivatives are new amphetamine-like stimulants that can evade detection when presently available methods are used for doping control. To prevent misuse of these banned substances in racehorses, development of a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method became the impetus for undertaking this study.
  
  
  METHODS
  Analytes were recovered via liquid-liquid extraction using methyl tert-butyl ether. Analyte separation was achieved on a hydrophilic interaction column using liquid chromatography and mass analysis was performed on a QTRAP mass spectrometer in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM). Analyte identification was carried out by screening for a specified MRM transition. Quantification was conducted using an internal standard. Confirmation was performed by establishing a match in retention time and ion intensity ratios comparison.
  
  
  RESULTS
  The method was linear over the range 0.2-50 ng/mL. The specificity was evaluated by analysis of six different batches of blank plasma and those spiked with each analyte (0.2 ng/mL). The recovery of analytes from plasma at three different concentrations was >70%. The limits of detection, quantification and confirmation were 0.02-0.05, 0.2-1.0 and 0.2-10 ng/mL, respectively. The matrix effect was insignificant. The intra-day and inter-day precision were 1.94-12.08 and 2.58-13.32%, respectively.
  
  
  CONCLUSIONS
  The method is routinely employed in screening for the eleven analytes in post-competition samples collected from racehorses in Pennsylvania to enforce the ban on the use of these performance-enhancing agents in racehorses. The method is sensitive, fast, effective and reliably reproducible.
authors: University of Pennsylvania, School of Veterinary Medicine, Department of Clinical Studies, New Bolton Center Campus, Kennett Square, PA, 19348, USA.
authors: Xiaoqing
authors: X
authors: Li
authors: Cornelius E
authors: CE
authors: Uboh
authors: Lawrence R
authors: LR
authors: Soma
authors: Ying
authors: Y
authors: Liu
authors: Fuyu
authors: F
authors: Guan
authors: Craig R
authors: CR
authors: Aurand
authors: David S
authors: DS
authors: Bell
authors: Youwen
authors: Y
authors: You
authors: Jinwen
authors: J
authors: Chen
authors: George A
authors: GA
authors: Maylin
mesh_terms: D000470:Alkaloids / Q000097:blood*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000097:blood*; D015198:Designer Drugs / Q000032:analysis*; D004300:Doping in Sports; D006736:Horses / Q000097:blood*; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D059625:Liquid-Liquid Extraction; D008738:Methyl Ethers / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods / Q000662:veterinary*
chemical_list: D000470:Alkaloids; D000697:Central Nervous System Stimulants; D015198:Designer Drugs; D008738:Methyl Ethers; C043243:methyl tert-butyl ether; C023665:cathinone