目的 建立一种检测乳粉中蔗果三糖、蔗果四糖、蔗果五塘、低聚半乳糖的高效液相色谱-蒸发光散射法(high performance liquid chromatography coupled with evaporative light scattering detector,HPLC-ELSD).方法 以水和乙腈为流动相梯度洗脱,利用糖柱分离,蒸发光散射检测器检测.考察了沉淀剂、酶解pH、温度和时间的影响.结果 经过优化,得到以乙腈为沉淀剂,酶解pH为6.0、酶解温度为25℃、酶解时间为50 min的最佳实验条件.该方法的线性范围均为0.05~2.0 mg/mL,半乳糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖检出限分别为0.02、0.02、0.01、0.02、0.02 mg/mL(S/N=3),回收率为92.52%~106.00%,相对标准偏差(relative standard deviation,RSD)低于5.12%(n=6).结论 该方法能准确可靠地检测乳粉中低聚果糖和低聚半乳糖的含量.
Determination of fructo oligosaccharide and galactooligosaccharides in milk powder by high performance liquid chromatography coupled with evaporative light scattering detector
Objective To establish a quantitative method for determination of GF2, GF3, GF4 and galactooligosaccharides in milk powder by high performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD). Methods The separation was performed on a carbohydrate column with the gradientelution of acetonitrile. The effects of precipitant, pH in solution, enzymolysis temperature and enzymolysis time on the enzymolysis efficiency were investigated. Results After optimization, the best experimental condition were as follows: acetonitrile was as precipitant, the enzymolysis pH was 6.0, the temperature was 25 , an℃ d the enzymolysis time was 50 min. Under these conditions, all targets could be well separated, and the linear rangers were from 0.05 to 2.0 mg/mL. The limits of detection of galactose, lactose, GF2, GF3 and GF4 were 0.02, 0.02, 0.01, 0.02,and 0.02 mg/mL (S/N), respectively. The recoveries were 92.52%~106.00% with RSDs less than 5.12% (n=6). Conclusion This method is accurate and reliable, which is suitable for the determination of fructo oligosaccharide and galactooligosaccharides in milk powder.
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万方数据
维普
