高效液相色谱法测定酸奶中的乳果糖

Determination of Lactulose in Dairy Products by High Performance Liquid Chromatography

建立酸奶中乳果糖的高效液相色谱检测方法。样品经调节pH沉淀蛋白质,超声提取后过滤,利用高效液相色谱柱分离,示差折光检测器检测,外标法定量。参考的色谱条件如下:以氨基柱(4.6 mm×250 mm,5μm,或具有同等性能的色谱柱)分离;以乙腈∶水∶甲醇=75∶19∶6为流动相,采用等梯度洗脱;流速:1.0mL/min;柱温:40℃;进样量:10μL。酸奶中乳果糖的添加量为25mg/100g~100mg/100g时,加标回收率为95.1%~104.9%,相对标准偏差为0.883%~2.78%。本方法检出限为5mg/100g;定量限为25mg/100g。该方法具有操作简单、结果准确、重复性好等优点,适用于酸奶中乳果糖的测定。

To establish a HPLC(high performance liquid chromatography)method for the determination of lactulose in yogurt.The samples were precipitated by pH,extracted by ultrasonic and filtered,separated by HPLC column,detected by differential refraction detector,and quantified by external standard method.The reference chromatographic conditions are as follows:separation by amino column(4.6mm×250mm,5μm,or column with equivalent properties);Take acetonitrile:water:methanol=75∶19∶6 as the mobile phase,and use equal degree elution;Flow rate:1.0mL/min;Column temperature:40℃;Injection volume:10μL.When the lactulose content was 25mg/100g~100mg/100g,the recoveries were 95.1%~104.9%with the relative standard deviations(RSDS)of 0.883%~2.78%.The detection limit of this method was 5mg/100g.The limit of quantitation was 25mg/100g.The method has the advantages of simple operation,accurate result and good repeatability,and is suitable for the determination of lactulose in yogurt.