Nicolas E C, Pfender K A
Bristol-Myers, USPNG, Evansville, IN 47721.
J Assoc Off Anal Chem. 1990 Sep-Oct;73(5):792-8.
A very fast and simple method for determination of nonphosphorylated thiamine in infant formula products, milk, and other nonfortified foods using reverse-phase ion-pairing liquid chromatography (LC) has been developed. Sample preparation consists of merely acid treatment to precipitate protein, followed by gravity filtration. No concentration, extraction, derivatization, or preliminary column cleanup is necessary. The chromatography is done on muBondapack C18 with an aqueous mobile phase containing 0.15% sodium hexane sulfonate, 20% MeOH, 1.5% HOAc, and 0.1% EDTA at a flow rate of 2.5 mL/min. Ultraviolet detection at 248 nm is used. A typical run takes 7 min, and 60 samples can be processed in 4 h. Results average from 96 to 104% of theory for the infant formula products analyzed. A 99 to 103% recovery of spike has been demonstrated. Method precision is good (2 to 4% RSD, short-term, and 2 to 5% RSD, long-term, depending on sample type). Peak separation from thiamine phosphate esters is achieved. Specificity is demonstrated by UV spectral scan and absorbance ratios. Equivalency to a microbial method (validated against the official AOAC fluorometric method) was established. The method is used for high-volume quality control testing of milk-based infant formula products in the ready-to-use, concentrate, or powder form.
已开发出一种非常快速且简单的方法，用于使用反相离子对液相色谱法（LC）测定婴儿配方奶粉产品、牛奶及其他非强化食品中的非磷酸化硫胺素。样品制备仅包括酸处理以沉淀蛋白质，然后进行重力过滤。无需浓缩、萃取、衍生化或柱前净化。色谱分析在μBondapack C18柱上进行，流动相为水相，含有0.15%的己烷磺酸钠、20%的甲醇、1.5%的乙酸和0.1%的乙二胺四乙酸，流速为2.5 mL/min。采用248 nm波长的紫外检测。一次典型的运行需要7分钟，4小时内可处理60个样品。所分析的婴儿配方奶粉产品的结果平均为理论值的96%至104%。已证明加标回收率为99%至103%。方法精密度良好（短期相对标准偏差为2%至4%，长期相对标准偏差为2%至5%，具体取决于样品类型）。实现了与硫胺素磷酸酯的峰分离。通过紫外光谱扫描和吸光度比证明了特异性。建立了与微生物法（根据官方AOAC荧光法验证）的等效性。该方法用于即食、浓缩或粉末形式的以牛奶为基础的婴儿配方奶粉产品的大量质量控制检测。
