Rapid and simple micromethod for the quantification of fluindione in human plasma using high-performance liquid chromatography

A new high-performance liquid chromatographic (HPLC) assay without any extraction procedure was developed for the quantification of fluindione in plasma using a 100-mu l sample volume and coumarin as the internal standard. A deproteinization procedure was coupled with a reversed-phase HPLC separation using a 250X4.6 mm I.D. C-18 column and a UV detector set at 280 nm. Peak height ratios were linear over the range 0.05 to 10 mu g/ml (correlation coefficient >0.998). The method was found to be highly reproducible, as indicated by the low value obtained for the coefficient of variation: C.V.less than or equal to 6.1% (n=10). The limit of quantification, estimated under the described conditions at a signal-to-noise ratio of three and with a C.V. lower than 20% for precision and accuracy, was 0.025 mu g/ml. The total turnaround time was 25 min. After storage of blood samples at concentrations of 0.1, 0.5 and 2.5 mu g/ml at room temperature and exposition to light for 120 h, no degradation of fluindione occurred. This micromethod is simple (no extraction step), fast and currently is being used for drug monitoring. (C) 1998 Elsevier Science B.V.