柱前衍生-高效液相色谱荧光法测定婴幼儿配方乳粉中低聚半乳糖含量

Determination of galactooligosaccharides in infant formula milk powder by precolumn derivatization-high performance liquid chromatography with fluorescence detection

中文关键词:  柱前衍生  高效液相色谱荧光法  婴幼儿配方乳粉  低聚半乳糖  响应面法

英文关键词:precolumn derivatization  high performance liquid chromatography with fluorescence detection  infant formula milk powder  galactooligosaccharides  response surface methodology

中文摘要:

      目的 建立柱前衍生-高效液相色谱荧光法测定婴幼儿配方乳粉中低聚半乳糖的检测方法。方法 样品经乙酸调节pH到4.5, 使用淀粉葡萄糖苷酶和β-半乳糖苷酶酶解、2-氨基苯甲酰胺衍生。经色谱柱分离, 荧光检测器检测。通过响应曲面设计优化衍生关键因素水平, 包括衍生剂浓度、衍生温度与衍生时间。结果 优化后的衍生剂浓度为0.45 mol/L、衍生温度为55 ℃与衍生时间为120 min。定量化合物3'-半乳糖基乳糖在10.0~100.0 mg/L范围内线性良好(r2=0.9993)。在低聚半乳糖添加水平为2.5、10.0、40.0 g/kg时, 回收率为92.5~102.7%, 相对标准偏差为3.69%~6.69% (n=6)。方法检出限为0.8 g/kg, 定量限为2.5 g/kg。结论 本方法操作简单、回收率高和重现性好, 可使用3'-半乳糖基乳糖对婴幼儿配方乳粉中的低聚半乳糖进行定量分析。

英文摘要:

      Objective To establish a method for the determination of galactooligosaccharides in infant formula milk powder by precolumn derivatization-high performance liquid chromatography with fluorescence detection. Methods The pH of the sample was adjusted to 4.5 by acetic acid, and starch glucosidase and β-galactosidase hydrolysis and 2-aminobenzamide derivatization. It was separated by chromatographic column and detected by fluorescence detector. The level of key factors for derivatization was optimized by response surface design, including derivatizer concentration, derivatization temperature and derivatization time. Results the optimized derivatizer concentration was 0.45 mol/L, the derivatization temperature was 55 ℃ and the derivatization time was 120 min. The linearity of the quantitative compound 3'-galactosyllactose was good in the range of 10.0?100.0 mg/L (r2=0.9993). When the addition levels of galactooligosaccharides were 2.5, 10.0 and 40.0 g/kg, the average recoveries were 92.5%?102.7% and the relative standard deviations were 3.69%?6.69% (n=6). The limit of detection was 0.8 g/kg and the limit of quantitation was 2.5 g/kg. Conclusion This method has the advantages of simple operation, high recovery and good reproducibility. 3'-galactosyllactose can be used for the quantitative analysis of galactooligosaccharides in infant formula milk powder.