Liquid-chromatographic assay of dexamethasone in plasma.

ABSTRACT

We report a simple, efficient method for removing dexamethasone from plasma by use of solid-phase extraction columns. The dexamethasone is then quantified by "high-performance" liquid chromatography with ultraviolet detection at 254 nm. Dexamethasone concentrations and peak-height ratios were linearly related over the range 5 to 200 micrograms/L. The lower limit of sensitivity was 5 micrograms/L. The average recoveries of dexamethasone and methylprednisolone (internal standard) were 72 and 71%, respectively. This procedure offers improved efficiency over that of previously described methods by decreasing analytical time and improving sample clean-up. Sensitive, specific, and relatively inexpensive, this method is suitable for most clinical applications.