凝胶色谱法测定婴幼儿配方乳粉中的α-乳白蛋白含量

Determination of α-lactalbumin in infant formula milk powder by gel chromatography

中文关键词:  凝胶色谱法  婴幼儿配方乳粉  α-乳白蛋白

英文关键词:gel chromatography  infant formula milk powder  α-lactalbumin

中文摘要:

      目的 建立凝胶色谱法检测婴幼儿配方乳粉中α-乳白蛋白的分析方法。方法 以盐酸胍为变性剂, 以2-巯基乙醇为还原剂, 断开蛋白质中的硫-硫(S-S)化学键, 形成展开的α-乳白蛋白的单体结构。样品经2根串联的凝胶色谱柱TSK-GEL G3000SWXL分离, 以6 mol/L盐酸胍缓冲液为流动相, 用紫外检测器在280 nm测定。结果 在0.25、1.25、2.5 g/100 g 3个浓度水平的平均回收率为98.0%~99.5%, 相对标准偏差小于3.90% (n=5), 检出限和定量限分别为0.01 g/100 g和0.03 g/100 g。结论 本方法操作简单、准确度高, 适用于婴幼儿配方乳粉中的α-乳白蛋白的测定。

英文摘要:

      Objective To establish a method for the determination of α-lactoalbumin in infant formula milk powder by gel chromatographic. Methods With guanidine hydrochloride as denaturant, and β-mercaptoethanol as reducer, the disulfide bond of protein was disconnected, then the single structure of the expanded α-lactalbumin was obtained. The samples were separated by 2 series connected TSK-GEL G3000SWXL columns, with 6 mol/L guanidine buffer as mobile phase, and measured by UV detector at 280 nm. Results The recoveries at 3 spiked levels (0.25、1.25、2.5 g/100 g) were 98.0%~99.5%. The relative standard deviations (RSDs) were less than 3.90% (n=5), the limit of detection (LOD) and limit of quantitation (LOQ) was 0.01 g/100 g and 0.03 g/100 g, respectively. Conclusion The established method is easy and accurate, which is suitable for the determination of α-lactalbumin in infant formula milk powder.