高效液相色谱法测定保健食品中α-硫辛酸含量的研究

Determinating the content of lipoic acid in health food by HPLC

目的建立保健食品中α-硫辛酸的测定方法。方法采用高效液相色谱法(HPLC),样品用流动相超声提取20 min,色谱柱:ODS-2HYPERSIL(4.60 mm×250 mm,5μm);流动相:0.125%(磷酸氢二钾+磷酸二氢钾,用磷酸调p H=3.5)+甲醇=35+65(V/V);流量:1.0 ml/min,检测波长:215 nm。结果硫辛酸在40 ng^4 000 ng范围内呈现良好的线性关系,相关系数为0.999997,检出限为2 ng,精密度试验RSD为0.53%(n=6);当样品添加浓度为5.33 g/100 g^22.7 g/100 g时,回收率为98.1%~102%。结论该方法操作简便、快速、可靠、重现性好,有效排除了杂质的干扰,可作为保健食品中α-硫辛酸的质量控制监测手段。

Objective To establish a method for determination of lipoic acid in health food by HPLC. Methods The samples were extracted by mobile phase in 20 min. The separation was performed on a ODS-2HYPERSIL（ 4. 60 × 250 mm,5 μm）; the mobile phase consisted of 0. 125%（ dipotassium phosphate ＋ monopotassium phosphate,with phosphoric acid tone p H = 3. 5） ＋methanol = 35 ＋ 65（ V / V）; the flow rate was 1. 0 ml / min; the detection wavelength was 215 nm. Results The lipoic acid showed to be linear over the range from 40 ng - 4 000 ng（ r = 0. 999997）. The limit of detection was 2 ng,and the RSD of measurement precision test was 0. 53%（ n = 6）. The recovery was 98. 1% - 102. 0%,while the contents of added standard were 5. 33 g /100 g - 22. 7 g /100 g. Conclusion This method is simple,accurate,reliable,and can effectively eliminate the interference of other impurities,which can be used for the quality control of paeoniflorin in health food.