Quantification of 3‐bromopyruvate in rat plasma by HPLC–MS/MS employing precolumn derivatization and the application to a pharmacokinetics study

Abstract A simple high‐performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method has been developed for the determination of 3‐bromopyruvate (3‐BrPA) in rat plasma for the first time. The analytes were separated on a C 18 column (100 × 2.1 mm, 1.7 μm) and a triple‐quadrupole mass spectrometry equipped with an electrospray ionization source was applied for detection. 3‐BrPA was extracted from rat plasma with protein precipitation, and then derivatized with 4‐nitro‐1,2‐phenylenediamine to obtain the mass signal because 3‐BrPA could not be detected in mass spectrometry. The method was fully validated according to the US Food and Drug Administration guidance. The method was linear over the concentration range 0.5–1,000.0 ng/ml for 3‐BrPA. The precision and accuracy, extraction recovery, and matrix effect were within acceptable limits. The method was then applied to support a pharmacokinetic study after 3‐BrPA and 3‐BrPA‐ l ‐Val‐ l ‐Ile (a dipeptide prodrug of 3‐BrPA, 3‐BrPA‐ l ‐Valine‐ l ‐isoleucine) had been administered to the Sprague–Dawley rats, respectively.