微孔板式微生物法测定婴幼儿配方乳粉中泛酸含量

目的：通过对国标微生物法的改进,采用微孔板的方法对婴幼儿配方乳粉中泛酸的含量进行测定研究。方法：采用国标微生物法的改进方法-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：实验室所采用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RSD为1.90%-5.32,准确度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6.91mg/100g,测定值结果间RSD为1.08%,回收率为89.7%-108.2%,说明方法精密度较高,对样品检测结果准确性较高,方法的系统误差小。结论: 采用的国标物法改进的微孔板式微生物法操作简便、结果准确、能够降低工作量,提高工作效率,能够应用于实验室对婴幼儿配方乳粉中泛酸含量的测定。

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

objective: to determine pantothenic acid in infant formula milk powder by microplate through improving the national standard microbiological method. Methods: microplate method was used to inoculate lactobacillus plantarum solution with suitable concentration into microplate containing sample solution and culture solution. After culture for a certain time, the absorbance was determined, according to the standard curve of pantothenic acid content and absorbance value, the pantothenic acid content in the sample was calculated. The method was evaluated by precision test, accuracy test and recovery test. Results: The Standard Curve of microplate microbiological method was linear, the Correlation Coefficient was r = 0.9965, the relative standard deviation of precision experiment was 1.90%-5.32, the accuracy test results showed that the pantothenic acid content of the quality control samples were all in the quantitative range, the average value was 6.91 mg/100g, the RSD of the determination was 1.08% , the recovery was 89.7%-108.2% , which showed that the method had high precision, the accuracy of sample detection is high and the systematic error of the method is small. Conclusion: The method is simple, accurate, can reduce the workload and improve the efficiency, and can be applied to the determination of pantothenic acid in infant formula milk powder in laboratory.