Simultaneous determination of lidocaine, prilocaine and the prilocaine metabolite o-toluidine in plasma by high-performance liquid chromatography

J. Klein, D. Fernandes, M. Gazarian, G. Kent, G. Koren

Research output: Contribution to journalArticle

54 Citations (Scopus)


An HPLC assay is described for the measurement of prilocaine and lidocaine (components of the local anesthetic cream EMLA) as well as the prilocaine metabolite, o-toluidine, in plasma. The method uses UV detection, is simple, sensitive and most important, only a single 200-μl plasma sample is needed for simultaneous analysis of prilocaine, lidocaine and o-toluidine with a detection limit of 4 ng/ml. The plasma, together with the internal standard (bupivacaine) is extracted with diethyl ether under alkaline conditions, followed by the extraction of the analytes from the organic phase into dilute sulphuric acid. An aliquot of the acid extract is injected onto the HPLC system and the effluent is monitored by a UV detector.

Original languageEnglish
Pages (from-to)83-88
Number of pages6
JournalJournal of Chromatography B: Biomedical Sciences and Applications
Issue number1
Publication statusPublished - 22-04-1994


All Science Journal Classification (ASJC) codes

  • Chemistry(all)

Cite this