婴幼儿配方乳粉中低聚半乳糖含量检测方法的前处理优化

Optimization of pretreatment for the determination method of galactose oligosaccharidein infant formula milk powder

中文关键词:  婴幼儿配方乳粉  低聚半乳糖  超声波  离心  离子色谱系统

英文关键词:infant formula milk powder  galactose oligosaccharide  ultrasonic  centrifugation  ion chromatography system

中文摘要:

      目的 优化国际通用的测定婴幼儿奶粉中GOS方法的前处理步骤, 提高检测结果的准确度。 方法 针对前处理条件增加了超声10 min的操作步骤; 在样液沉降蛋白时, 进行离心, 确定了最佳的离心条件: 10000 r/min, 10 min。此外优化了梯度洗脱时淋洗液比例。经离子色谱检测, 外标法定量发现GOS有5个不同特征峰, 经验证确定以GOS2作为GOS定量峰, 计算GOS含量。结果 GOS质量浓度在5~100 μg/mL范围内标准曲线的相关系数(r2)均大于0.995, 在质量分数为0.6、1.2、2.0、3.0、4.0 g/kg 5个加标水平下, 方法回收率为100%~120%, 相对标准偏差为0.22%~6.40% (n=2)。结论 该优化后的方法, 样品提取更加充分, 样品峰分离效果更好, 回收率与重复性良好, 结果准确性更高,对准确检测婴幼儿配方乳粉中GOS的含量具有一定的意义。

英文摘要:

      Objective To optimize the pretreatment conditions of the international method for the determination of GOS to improve the accuracy of detection results. Methods Ten min ultrasonic treatment was added to the current pretreatment method and centrifugation was carried out for sedimentation proteinto. The optimal centrifugation conditions were determined: 10000 r/min, 10 min. In addition, the eluent ratio of gradient elution was optimized. Five different characteristic peaks of GOS were found by ion chromatography detection and quantitative external standard method. GOS2 was verified as GOS quantitative peak to calculate GOS content. Results The correlation coefficient (r2) of the standard curve was greater than 0.995 in the range of 5-100 μg/mL. The recovery rates were 100.0% to 120.0% and the relative standard deviations were 0.22% to 6.40% (n=2) at the standard levels of 0.6, 1.2, 2.0, 3.0 and 4.0 g/kg. Conclusion The optimized method is more effective in sample extraction, better in separation of sample peak and better in recovery and repeatability, and higher in accuracy, which can satisfy the requirement of determination of GOS in infant formula milk powder.