高效液相色谱柱前衍生法测定食品中的营养型和非营养型抗坏血酸

应用高效液相色谱柱前衍生法分离测定食品中的营养型 (L型 )和非营养型抗坏血酸 (D异型 )总量。样品中的抗坏血酸经活性炭脱氢 ,在 pH值 5 0的醋酸盐缓冲液中与邻苯二胺进行柱前衍生 ,用磷酸氢二钠、V 二乙胺的水溶液 (pH =7 0 ) ]∶ V (乙腈 ) =90∶10作为流动相 ,在InertsilODS 3柱上得以完全分离 ,经荧光检测器Ex=3 46nm ,Em=42 8nm下检测 ,外标法定量。试验结果表明 ,各组分在 2～ 2 0 μg/mL的浓度范围内 ,线性相关系数均为0 999,RSD值为 3 5 % ,回收率可达 99%～ 10 1%。

HPLC Pre-column Derivation for Measuring Nutritive and Non-nutritive Ascorbic Acid

A method was developed for testing the total contents of nutritive (L Ascorbic Acid) and non-nutritive Vitamin C(D Isoascorbic Acid) in food by HPLC-Pre-Column derivation method. The ascorbic acid in sample was dehydrogenated with acid active carbon, followed by pro-column derivation with o-phenylenediamine in acetic acid puffer solution (pH=5.0). The mobile phase was 10% acetonitrile in the solution (pH=7.0) containing 20 mmol/L disodium hydrogen phosphate and 5 mmol/L diethylamine. The two kinds of Vitamin C were separated completely on Inertsil ODS-3 column, with fluoescence detector for monitoring (Ex=346nm, Em=428nm) and peak area method for quantification. In the concentration range of 2～20 μg/mL, regression factor was 0.999. The RSD were within 3.5%. The percentage of recovery rate during analysis was between 99%～101%.