Zientek Keith D, Anderson Danielle F, Wegner Kirsten, Cole Cynthia
University of Florida, College of Veterinary Medicine, Gainesville, Florida, USA.
J Anal Toxicol. 2007 Mar;31(2):87-92. doi: 10.1093/jat/31.2.87.
A method for the extraction and quantitation of procaine in equine plasma was developed for use with liquid chromatography-mass spectrometry (LC-MS). Procaine was isolated from equine plasma by liquid-liquid extraction at pH 11 with dichloromethane using procaine-d10 as an internal standard. Quantitation was achieved by LC-MS using a 3-microm C-18 column coupled to an electrospray ionization source on a linear ion-trap mass spectrometer. The limit of detection and limit of quantitation was determined to be 50 and 200 pg/mL, respectively. The lowest limit of detection determined by previous methods was 1 ng/mL. Administration samples were obtained as part of a larger study to determine a regulatory limit for procaine in racehorses and procaine concentrations were determined using this method.
