摘要   目的：建立比色法测定复方制剂中盐酸麻黄碱含量的方法。 方法：根据盐酸麻黄碱在一定pH条件下，可与溴麝香草酚蓝(BTB)反应生成稳定的络合物这一特性，选择414nm波长处测定其含量。 结果：盐酸麻黄碱在0.005-0.04mg/ml浓度范围内与吸收度成良好的线性关系，平均回收率为99.94%，RSD为0.2921%（r=0.9992），制剂中其它成分对其无干扰。结论：本含量测定方法简便、快速、准确、专属性强、重复性好，适用于复方制剂中盐酸麻黄碱的含量测定。
        关键词  盐酸麻黄碱  比色法  含量测定

Determination of Ephedrine Hydrochloride in Compound Preparation by Colorimetry
Chen Shuanglu, Guo Donghua, Bai Yalin (Tianjin Children Hospital, Tianjin, 300074, P. R. China)
ABSTRACT Objective: To establish a colorimetric method for the content determination of ephedrine hydrochloride in compound preparation. Method: The proposed method involves forming colored ion-pair from ephedrine hydrochloride and bromothymol blue at pH 6.5 extracting the ion-pair thus into chloroform and measuring the absorbance chloroform solution at 414nm. Result: The ephedrine hydrochloride presented a good linear relationship within a range of 0.005-0.04mg•ml-1. The average recovery was 99.94% (RSD=0.2921%). Conclusion: The method is simple, rapid, specific and repeatable. It can be used for content determination of ephedrine hydrochloride in compound preparation.
KEY WORDS Ephedrine hydrochloride; Colorimetry; Content determination