微生物法测定婴幼儿乳粉中叶酸含量方法优化

Optimization of Microbiological Method for Determination of Folic Acid in Infant Milk Powder

目的:建立微生物法测定婴幼儿乳粉中叶酸含量的方法。方法:利用样品中叶酸的含量与一定条件下鼠李糖乳杆菌数量呈正比的关系,将鼠李糖乳杆菌菌悬液接种至含有叶酸的试样液中,通过对菌悬液的接种量、培养时间、灭菌时间等关键过程的细节优化,测定其吸光度值,再通过叶酸标准曲线来计算样品中叶酸的最终含量,并通过分析标准曲线的线性关系、重复性实验和回收率实验来验证此方法的可靠性。结果:标准曲线相关系数r^(2)=0.997 6,相对标准偏差(RSD)为1.20%,平均回收率为95.9%。结论:此优化方法操作简便、稳定可靠、重复性好,对关键的控制点也有精准的把控,最后得到了满意的实验结果。

Objective:To establish an optimized method for the determination of folic acid in infant milk powder by microbiological method.Methods:The folic acid content in the sample was proportional to the number of Lactobacillus rhamnosus under certain conditions.The suspension of Lactobacillus rhamnosus was inoculated into the sample solution containing folic acid,and the absorbance value was determined by optimizing the inoculation amount,culture time,sterilization time and other key processes of the suspension,and then the final content of folic acid in the sample was calculated by folic acid standard curve.Finally,the reliability of this method is verified by analyzing the linear relationship of standard curve,repeatability experiment and recovery experiment.Results:The correlation coefficient of the standard curve was r^(2)=0.9976,the relative standard deviation was 1.20%,and the average recovery was 95.9%.Conclusion:The optimization method is simple,stable,reliable,reproducible,and can accurately control the key control points.Finally,satisfactory test results are obtained.