Simultaneous separation and confirmation of amphetamine and related drugs in equine plasma by non-aqueous capillary-electrophoresis-tandem mass spectrometry.

A non-aqueous capillary electrophoresis-mass spectrometry (NACE-MS) method was developed for simultaneous separation and identification of 12 amphetamine and related compounds in equine plasma. Analytes were recovered from plasma by liquid-liquid extraction using methyl tertiary butyl ether (MTBE). A bare fused-silica capillary was used for separation of the analytes. Addition of sheath liquid to the capillary effluent allowed the detection of the analytes by positive electrospray ionization mass spectrometry using full scan data acquisition. The limit of detection (LOD) for the target analytes was 10-200 ng/mL and that of confirmation (LOC) was 50-1000 ng/mL in equine plasma. Capillary electrophoresis (CE) and mass spectrometry (MS) parameters were optimized for full CE separation and MS detection of the analytes. Separation buffer comprised 25 mM ammonium formate in acetonitrile/methanol (20: 80, v/v) plus 1 M formic acid. Sheath liquid was isopropanol-water-formic acid (50:50:0.5, v/v/v). Samples were hydrodynamically injected and separated at 25 kV. Analytes were electrokinetically separated and mass spectrometrically identified and confirmed. This simple, fast, inexpensive and reproducible method was successfully applied to post race equine plasma and research samples in screening for amphetamine and related drugs.

Postmortem tissue samples: an alternative to urine and blood for drug analysis in racehorses.

Although urine is the sample of choice for drug tests in racehorses, it is rarely obtained following the sudden death of a racehorse on the track while racing. The purpose of this study was to demonstrate the significance of postmortem tissue samples as an alternative to urine and blood samples in equine drug analysis following the sudden death of a racehorse on the track while participating in a competitive race. Postmortem tissue samples were frozen (-80 degrees C) until analyzed. A 30-40-g portion of each organ was homogenized in a 0.1 M phosphate buffer (pH 7.4), deproteinized, hydrolyzed with beta-glucuronidase, extracted, and screened by thin-layer chromatography and immunoassay. Samples that initially tested positive for drug(s) were then extracted using high-flow, solid-phase extraction cartridges. The eluates were analyzed by gas chromatography-mass spectrometry. The presence of butorphanol in horses HB355 and CD387, pentobarbital in horse HO940, and ergotamine in horses HO940 and CD387 was detected and confirmed. Thus, in the absence of urine and blood samples following sudden death, postmortem tissue samples are equally useful for forensic toxicological investigations of racehorses.