Nicolas E C, Pfender K A, Aoun M A, Hemmer J E
Bristol-Myers U.S. Pharmaceutical and Nutritional Group, Evansville, IN 47721.
J Assoc Off Anal Chem. 1990 Jul-Aug;73(4):627-31.
A fast and simple method for determination of taurine in infant formulas has been developed. The sample preparation uses disposable ultrafiltration cartridges to remove protein and clarify the sample. Hydrolysis is avoided, simplifying the procedure and increasing efficiency. One mL sample is centrifuged in a cartridge for 45 min. The filtrate is diluted with pH 2.2 citrate buffer and injected into a high performance amino acid analyzer. A cation-exchange column (sodium phase) is used with a single buffer eluant and an isocratic chromatographic program. Colorimetric detection is performed following post-column ninhydrin reaction. Chromatographic resolution from other ninhydrin-positive compounds is excellent. Average recoveries for 3 levels of spike for various products were 100-102%. Precision is 1-3% RSD, depending on product. Linearity, specificity, and ruggedness are excellent. The method is applicable to quality control testing of milk-based, soy-based, and prehydrolyzed protein-based infant formulas in the ready-to-use, concentrate, and powder forms. A variety of commercially available infant formulas from different manufacturers were analyzed and all were found to contain taurine levels comparable to human milk. Some human milk and cow's milk samples were also analyzed and results compare well with literature values.
已开发出一种快速简便的测定婴儿配方奶粉中牛磺酸的方法。样品制备使用一次性超滤柱去除蛋白质并使样品澄清。避免了水解，简化了操作流程并提高了效率。将1 mL样品在柱中离心45分钟。滤液用pH 2.2的柠檬酸盐缓冲液稀释后注入高效氨基酸分析仪。使用阳离子交换柱（钠相），采用单一缓冲洗脱液和等度色谱程序。柱后茚三酮反应后进行比色检测。与其他茚三酮阳性化合物的色谱分离效果极佳。不同产品3个加标水平的平均回收率为100 - 102%。精密度为1 - 3%相对标准偏差，取决于产品。线性、特异性和耐用性都很好。该方法适用于即食型、浓缩型和粉状的以牛奶为基础、大豆为基础以及预水解蛋白为基础的婴儿配方奶粉的质量控制检测。对不同制造商的多种市售婴儿配方奶粉进行了分析，发现所有奶粉中牛磺酸含量与母乳相当。还分析了一些母乳和牛奶样品，结果与文献值比较吻合。
