高效液相色谱-蒸发光散射检测法与酶法检测UHT灭菌乳中乳果糖含量的对比研究

A Comparative Study of the Determination of Lactulose in Ultra High Temperature Sterilized Milk Using High Performance Liquid Chromatography with Evaporative Light-Scattering Detector and Enzymatic Hydrolysis

采用液相色谱法分离、蒸发光散射检测器检测,外标法定量测定超高温瞬时灭菌乳中乳果糖的含量。采用盐酸沉淀蛋白,氨基色谱柱分离,流动相为75%乙腈溶液。该方法能使乳果糖得到很好分离,精密度为0.77%(n=6),平均回收率为98.7%~102.6%。高效液相色谱-蒸发光散射检测法较酶法操作简便、省时、重复性好,可以根据实验需求选择使用。

An analytical method to determine lactulose in ultra high temperature （UHT） sterilized milk by liquid chromatographic separation, evaporative light-scattering detection and external standard quantitation is described in this paper. After the protein was precipitated by adding hydrochloric acid, the separation was performed with satisfactory results on a NH2 column using 75% acetonitrile in water as the mobile phase. The precision expressed as relative standard deviation （n = 6） was 0.77%, and the average recovery was in the range of 98.7%-102.6%. This method was simpler and less time consuming with good repeatability than traditional enzymatic hydrolysis method. It can provide an alternative way of determining lactulose in UHT sterilized milk.