Quantification of furosemide in camel plasma by high resolution mass spectrometry, application on pharmacokinetics

We developed and validated a high resolution liquid chromatography mass spectrometry method for the quantification of furosemide in camel plasma which was used for a pharmacokinetic study in camels. Plasma samples were extracted by supported liquid extraction and furosemide and internal standard (furosemide-D5) were separated on a an Agilent Zorbax XDB C18 column (50 mm × 2.1 mm i.d., 3.5 µm). Data was acquired in full-scan mode over a mass range of 200–400 Da in negative electro spray mode at a resolution of 70,000. Linear calibration curves were obtained over the concentration ranges of 1.0-10,000 ng/mL. The validated method was then successfully applied in evaluating the pharmacokinetics and metabolites of furosemide in 6 camels (Camelus dromedarus) and we were able to advice on a withdrawal time of furosemide treatment before racing. This article is protected by copyright. All rights reserved.