建立高效液相色谱法测定乳粉和液态奶中牛磺酸含量。样品用水溶解，超声提取10 min，提取液经亚铁氰化钾和乙酸锌沉淀蛋白后，离心，上清液用异硫氰酸苯酯和三乙胺衍生化，室温衍生1 h，加入正己烷为衍生化终止剂，静置分层，下层溶液用水定容后过0.22 μm微孔滤膜，过滤液经Diamonsil AAA氨基酸分析柱（4.6×250 mm，5 μm）分离，以0.05 mol/L乙酸钠水溶液（pH值=6.50）和甲醇/乙腈（1/1，V:V）为流动相进行梯度洗脱。采用外标法定量，在5.0~40 μg/mL线性范围内相关系数（r）大于0.999，线性关系良好，定量限为5 mg/100 g（S/N≥10），添加水平为5、10、25 mg/100 g时，回收率范围在90%~108%之间，相对标准偏差范围为1.16%~2.24%。结果显示，本方法准确、可靠，满足乳粉和液态奶中牛磺酸含量的有效确定，特别对于特膳奶粉比GB方法更适合样品中牛磺酸含量的有效检测。

A high performance liquid chromatography (HPLC) method was developed for the determination of taurine in milk powder and liquid milk. The milk samples were dissolved in water, subjected to ultrasonic-assisted extraction for 10 min, precipitated with zinc acetate and potassium ferrocyanide, and centrifuged. The resultant supernatant was derivatized with phenyl isothiocyanate and triethylamine at room temperature for 1 h, before addition of n-hexane (to terminate derivatization) and standing (to allow phase separation). The lower layer solution was diluted with water and the obtained solution was filtered through a 0.22 μm microporous membrane. The filtrate was further separated using an amino acid analysis column (Diamonsil AAA, 4.6 × 250 mm, 5 μm) and a mobile phase for gradient elution with an aqueous sodium acetate solution (0.05 mol/L, pH=6.50) and acetonitrile / methanol (1/1, V/V). Quantification was performed using external standards. Good linearity was obtained in the concentration range of 5.0~40 μg/mL with correlation coefficients greater than 0.999, the limit of quantification as 5 mg/100 g (S/N≥10). At spiking levels of 5, 10 and 25 mg taurine /100 g r, the average recovery was in the range of 90%~108% with the relative standard deviation within 1.16%~2.24%. The results show that the analysis method established in this study is accurate and reliable, and meet the requirements for efficient analysis of taurine in milk powder and liquid milk. Compared with the GB method, this method is more suitable for effective detection of taurine in special diet milk powder.

国家重点研发计划项目（2017YFF0211303）；国家质检总局科技计划项目（2016IK220）；中央引导地方科技发展专项（YDZX20173100004528）；长三角科技合作项目（17395810102）；上海市科委科研项目(17DZ2293700）