高效液相色谱法测定合剂中苯甲酸的含量

目的：采用高效液相色谱法（HPLC法）测定合剂（前胡桑菊合剂、五柑合剂、胃肠合剂、佛耳合剂）中苯甲酸的含量。方法用乙酸乙酯提取合剂中的苯甲酸,提取液浓缩后采用HPLC法进行测定。选择Thermo Syncronis C18（250 mm×4.6 mm,5μm）,以甲醇-磷酸二氢钾（0.05 mol/L）（45：55）为流动相,流速为1.0 ml/min,柱温为30℃,检测波长为226 nm。结果苯甲酸回归方程Y=5835283.5514 X-23440.3860（R=0.9999）,在0.020~0.1018 mg/ml范围内线性关系良好；前胡桑菊合剂、五柑合剂、胃肠合剂、佛耳合剂平均回收率分别为99.79%、99.37%、99.34%、99.92%；RSD分别为0.35%、0.10%、0.76%、0.36%（n=3）。结论测定方法简便、准确、专属性强、重现性良好。

Determination of benzoic acid in mixture by HPLC

Objective To establish a high performance liquid chromatography（HPLC） method for the determination of（Qianhu Sangju mixture, Wugan mixture, Weichang mixture, Foer mixture） benzoic acid. Methods The extraction mixture of benzoic acid with ethyl acetate, the concentrated extract was determined by HPLC method. Select the thermo syncronis C-18（250 mm×4.6 mm, 5 μm）, with methanol and potassium dihydrogen phosphate（0.05 mol/L） （45：55） as mobile phase, flow rate of 1.0 ml/min, column temperature was 30℃ , the detection wavelength was 226 nm. Results Benzoic acid regression equation was Y=5835283.5514 X-23440.3860（R=0.9999）, in 0.020~0.1018 mg/ml the linear relationship was good; Qinhu Sangju mixture, Wugan mixture, Weichang mixture, Foer mixture the average recovery rate was 99.79%, 99.37%, 99.34%, 99.92%;RSD=0.35%, 0.10%, 0.76%, 0.36%（n=3）. Conclusion This method is simple and accurate, with a strong specificity, so it can be used as preparation for the quality control.