University of Pennsylvania, School of Veterinary Medicine, Department of Clinical Studies, New Bolton Center Campus, Kennett Square, PA, 19348, USA.
Rapid Commun Mass Spectrom. 2014 Jan 30;28(2):217-29. doi: 10.1002/rcm.6778.
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.
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.
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.
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.
瓜那酮衍生物是新型苯丙胺类兴奋剂，当目前使用的兴奋剂检测方法用于药物检测时，这些物质可以逃避检测。为了防止这些违禁物质在赛马中被滥用，开发液相色谱/串联质谱（LC/MS/MS）方法成为开展本研究的动力。
通过使用甲基叔丁基醚进行液-液萃取来回收分析物。使用亲水作用色谱柱进行分析物分离，在正电喷雾电离（ESI）模式下的 QTRAP 质谱仪上进行质量分析，并采用多重反应监测（MRM）。通过筛选指定的 MRM 跃迁来进行分析物鉴定。使用内标进行定量。通过保留时间和离子强度比比较来确证。
该方法在 0.2-50ng/mL 范围内呈线性。通过分析六个不同批次的空白血浆和每个分析物（0.2ng/mL）加标血浆来评估方法的特异性。在三个不同浓度下，分析物从血浆中的回收率>70%。检测限、定量限和确证限分别为 0.02-0.05、0.2-1.0 和 0.2-10ng/mL。基质效应不显著。日内和日间精密度分别为 1.94-12.08%和 2.58-13.32%。
该方法已常规用于检测宾夕法尼亚州赛马比赛后采集的赛马样本中十一种分析物，以执行对这些提高赛马比赛表现的兴奋剂的禁用规定。该方法灵敏、快速、有效且重现性可靠。
