High performance liquid chromatographic determination of dextromethorphan and its metabolite in human urine.

A reverse-phase high-performance liquid chromatographic method was established for the determination of dextromethorphan (DM) and its metabolite dextrophan (DX) in human urine. The sample was purified by an acid-base extraction followed by HPLC analysis on a phenyl column. The eluate was monitored by fluorescence at 280 nm (excitation) and 310 nm (emission). The limit of detection of DM was 0.023 mg.L-1. The within-day and between-day RSD% of DM and DX were all lower than 5%. The average recovery was 104.78%.