HPLC法测定L-抗坏血酸中的有关物质及探讨

Determination and Discussion of Related Substances in L-Ascorbic Acid by HPLC

目的:建立HPLC法测定L-抗坏血酸中的有关物质,并分析L-抗坏血酸中部分降解产物的产生机理。方法:采用Alltima Amino色谱柱(250 mm×4.6 mm,5μm),以磷酸盐缓冲液(取磷酸二氢钾6.8 g,用水溶解并稀释至175 m L,滤过,用水稀释至1000 m L)-乙腈(1︰2,v/v)为流动相;流速:1.0 m L·min-1,检测波长:210 nm,柱温:45℃,进样量:20μL。结果:样品中的杂质2-酮基古洛糖酸和2-酮基古洛糖酸甲酯能被很好地检出,各杂质与主峰间的分离度良好,检测限为0.02μg;并分析了部分降解产物的降解机理。结论:本方法简便,结果准确,为L-抗坏血酸中有关物质的控制提供了参考。

Objective： To establish an HPLC method for the determination of the related substances in L-ascorbic acid and analyze the generation mechanism of part degradation products of L-ascorbic acid. Methods： An Alltima Amino column（250 mm×4.6 mm, 5 μm） was used and the mobile phase was phosphates buffer（potassium dihydrogen phosphate 6.8 g, dissolved with 175 m L water, filtered, and then diluted to 1000 m L with water）-acetonitrile（1︰2, v/v）. The flow rate was 1.0 m L·min-1; the detection wavelength was 210 nm; the injection volume was 20 μL, and the column temperature was 45 ℃. Results： The related substances 2-ketogulonate and 2-methyl ketogulonate could be well separated. The separation of impurity peaks and main peak was good with the limit of detection being 0.02 μg. In addition, the degeneration mechanism of part degradation products was analyzed. Conclusion： The method is simple and accurate, providing reference of the control of the related substances in L-ascorbic acid.