Development and validation of a high-performance liquid chromatographic method for the determination of γ-hydroxybutyric acid in rat plasma

A method for the determination of γ-hydroxybutyric acid (GHB) in rat plasma was developed using solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) with UV detection. GHB was isolated from plasma using strong anion-exchange SPE columns. The chromatographic separation was performed on a C18 Aqua column. The lower limit of quantification was 10 μg/ml using 60 μl of plasma. The linearity of the calibration curves was satisfactory as indicated by correlation coefficients of >0.990. The within-day and between-day precision were <10% (n=24), the accuracy was nearly 101%. Plasma concentrations in rats after GHB infusion determined by HPLC–UV were compared with the corresponding concentrations determined with a validated gas chromatographic–mass spectrometric method by orthogonal distance regression. A good correlation was observed and a t-test indicated no significant differences from 0 and 1 for the intercept and slope, respectively.