目的:建立舒巴坦钠中2-乙基己酸的测定方法。方法:采用聚乙二醇为固定相的毛细管色谱柱、氢火焰离子检测器(FID);3-环己丙酸为内标物;柱温采用程序升温。结果:2-乙基己酸浓度在0.078～1.564mg·ml~(-1)范围内线性关系良好r=0.999 6,定量限为15.6ng,检测限4.7ng。结论:方法简单,结果准确,可用于舒巴坦钠中2-乙基己酸检测。 Objective: To establish a method for the determination of 2-ethylhexanoic acid in sulbactam sodium. Methods: Capillary column with polyethylene glycol as stationary phase, hydrogen flame ionization detector (FID) and 3-cyclohexyl propionic acid as internal standard were used. Results: The linearity of 2-ethylhexanoic acid in the range of 0.078-1.564 mg · ml -1 was good (r = 0.999 6), the limit of quantification was 15.6ng and the limit of detection was 4.7ng. Conclusion: The method is simple and the results are accurate. It can be used for the determination of 2-ethylhexanoic acid in sulbactam sodium.