HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR AN AUTOMATED-DETERMINATION OF LOCAL-ANESTHETICS IN HUMAN PLASMA

A method is described that allows the rapid and precise determination of the local anaesthetics bupivacaine and etidocaine from biological f luids. This method uses a fully automated system with solid-phase extr action in combination with a column-switching technique. Both sample e xtraction on a LiChrocart pre-column and elution onto the analytical L iChrospher column, were performed automatically and concomitantly usin g conventional HPLC equipment in conjunction with an OSP-2 on-line sam ple preparator from Merck combined with UV detection. Recoveries were found to be 96.7 and 96.4% for 2 mu g/ml bupivacaine and etidocaine, r espectively. Lower limits of quantification were found to be 0.05 mu g /ml plasma for both of the compounds.