Simultaneous analysis of ketamine and bupivacaine in plasma by high-performance liquid chromatography

A reversed-phase HPLC technique for the simultaneous measurement of both bu pivacaine and ketamine in plasma is described. Plasma samples (0.5 mi) were prepared using a rapid and simple back-extraction technique. Resolution of both analytes and the internal standard, desipramine, from medicines coadm inistered to surgical paediatric patients was obtained using a 5 mu m cyano (CN) (250x4.6 mm) column and a mobile phase comprising methanol-acetonitri le-orthophosphoric acid-0.01 M sodium dihydrogenphosphate (200:80:2:718). G ood sensitivity for both analytes was observed using UV detection at a wave length of 215 nm. The method has been validated according to the criteria e stablished by the Journal of Chromatography B. (C) 1999 Elsevier Science BN . All rights reserved.