摘要：β-Hydroxybutyric acid-p-phenetidide (B), ethoxybenzamide (EB), and caffeine in antipyretic preparations were determined by gas-liquid chromatography with hydrogen flame ionization detector on a 2-m column of 1.3% Epon resin at 165°. B was changed to trimethylsilyl derivative by using a silyl reagent consisting of hexamethylidisilazane and trimethylchlorosilane. EB was slightly affected by using hexamethyldisilazane : trimethylchlorosilane (8 : 2) directly. Then the reagent was diluted withte trahydrofuran : chloroform (1 : 1) mixture and the effect can be eliminated. Determination was made successfully by the internal standard method using phenanthrene.
