McSharry W O, Savage I V
J Pharm Sci. 1980 Feb;69(2):212-4. doi: 10.1002/jps.2600690227.
Acetaminophen (I), guaifenesin (II), and dextromethorphan hydrobromide (III) were separated and quantitated simultaneously in cough syrup by high-pressure liquid chromatography. A chemically bonded octadecylsilane stationary phase was used with a mobile phase of 48% (v/v) aqueous methanol. The mobile phase pH was stabilized to 4.2 by adding formic acid--ammonium formate buffer (approximately 0.4%). The internal standard was o-dinitrobenzene. Retention volumes were 4 ml for I, 6 ml for II, 11 ml for the internal standard, and 20 ml for III. Inactive syrup components did not interfere, permitting direct diluted sample injection. Results on active ingredients were essentially 100% of the claim, with standard deviations of +/- 1.5, 1.2, and 2.1% for I, II, and III, respectively.
通过高压液相色谱法同时分离并定量咳嗽糖浆中的对乙酰氨基酚（I）、愈创甘油醚（II）和氢溴酸右美沙芬（III）。使用化学键合十八烷基硅烷固定相，流动相为48%（v/v）的甲醇水溶液。通过添加甲酸 - 甲酸铵缓冲液（约0.4%）将流动相pH稳定在4.2。内标物为邻二硝基苯。I的保留体积为4 ml，II为6 ml，内标物为11 ml，III为20 ml。糖浆中的非活性成分不产生干扰，允许直接进样稀释后的样品。活性成分的结果基本为标示量的100%，I、II和III的标准偏差分别为±1.5%、1.2%和2.1%。
