微孔板式微生物法测定婴幼儿配方乳粉中泛酸含量

Determination of pantothenic acid content in infant formula milk powder by microplate microbial method

目的采用微孔板式微生物法对婴幼儿配方乳粉中泛酸含量进行测定。方法采用微孔板法将合适浓度的植物乳杆菌液接种至含有试样液与培养液的无菌微孔板中,培养一定时间后测定吸光度值,根据泛酸含量与吸光度值的标准曲线计算出试样中泛酸的含量。通过精密度实验、准确度实验、加标回收实验对此方法进行评价。结果微孔板式微生物法的标准曲线线性良好,相关系数r=0.9965,精密度实验的相对标准偏差(relative standard deviation,RSD)为1.90%~5.32%。实验结果表明质控样品的泛酸含量各平行检测值均在定量值范围内,且平均值为6.91 mg/100 g,测定值结果间RSD为1.08%,回收率为89.7%~108.2%。结论该方法操作简便、结果准确,能够降低工作量,提高工作效率,且方法精密度较高,对样品检测结果准确性较高,方法系统误差小,能够应用于实验室对婴幼儿配方乳粉中泛酸含量的测定。

Objective To determine the pantothenic acid content in the infant formula milk powder by a microplate microbial method.Methods The Lactobacillus plantarum solution with appropriate concentration was inoculated into a sterile microplate containing the sample solution and the culture solution by using a microplate method,the absorbance value after culture for a certain time was measured,and the content of pantothenic acid in the sample was calculated according to the standard curve of the pantothenic acid content and the absorbance value.The method through precision experiment,accuracy experiment and standard addition recovery experiment was evaluated.Results The linearity of the standard curve of the microplate microbial method was good,with the correlation coefficient r=0.9965,and the relative standard deviation(RSD)of the precision experiment was 1.90%-5.32%.The experimental results showed that the parallel detection values of pantothenic acid content in quality control samples were within the quantitative value range,and the average value was 6.91 mg/100 g;the RSD between the determination results was 1.08%;the recovery rate was 89.7%-108.2%.Conclusion This method is simple,accurate,can reduce the workload and improve the efficiency,and the method has high precision,high accuracy of sample test results.The method system error is small.It can be applied to the laboratory to determine the content of pantothenic acid in infant formula milk powder.