Determination of eflornithine enantiomers in plasma, by solid-phase extraction and liquid chromatography with evaporative light-scattering detection

A bioanalytical method for determination of eflornithine (DFMO) in 1000 μL human plasma has been developed and validated. DFMO and the internal standard (IS) were analysed by liquid chromatography with evaporative light-scattering detection (ELSD). Separation was performed on a Chirobiotic TAG (250 mm × 4.6 mm) column with ethanol (99.5%):0.01 mol/L acetic acid-triethylamine buffer at the rate of 25:75% (v/v) with flow rate of 1.0 mL/min. For d-DFMO in plasma the inter-assay precision was 6.5% at 75 μmol/L, 6.6% at 375 μmol/L and 5.8% at 750 μmol/L. For l-DFMO in plasma the inter-assay precision was 10.4% at 75 μmol/L, 6.5% at 375 μmol/L and 5.0% at 750 μmol/L. The lower limit of quantification (LLOQ) was determined to 25 μmol/L where the precision was 4.3% and 5.7%, respectively.