Determination of terbutaline enantiomers in biological samples using liquid chromatography with coupled columns

The purpose of this work was to develop and validate a method for the separation and determination of the enantiomers of terbutaline in plasma and intestinal juice. Terbutaline was extracted from plasma and intestinal juice by liquid-solid extraction on small C18 cartridges. The extract was then analyzed by coupled column liquid chromatography with amperometric detection. For chiral separation a beta-cyclodextrin phase was used. The within-day variation (Cv) on spiked plasma samples was in the range 0.8-6.4% at 3.8-33.8 nmol/liter for the (-)-enantiomer, and 2.6-23.0% at 1.3-11.3 nmol/liter for the (+)-enantiomer. The between-day variation on spiked plasma samples was 5.5% at 10.7 nmol/liter and 13.6% at 4.3 nmol/liter for the (-)-and (+)-enantiomers, respectively. The within-day variation for intestinal juice was in the range 0.7-1.5% at 5.6-30.0 mumol/liter for the (+)-enantiomer.