Abstract: A rapid quantitative method for the determination of taurine in milk powder by high performance liquid chromatography (HPLC) with ortho-phthaladehyde (OPA) as pre-column derivatization reagent has been developed. After automated derivatization in the autosampler, the standards and samples were directly into the HPLC system for analysis. An Ultimate AQ-C18 (2.1 mm × 100 mm, 3 μm) was used for the analysis at 40 ℃. The separation was carried out using a mobile phase consisting of acetonitrile and 10 mmol/L sodium acetate solution (pH 4.2) at a flow rate of 0.4 mL/min. The linear range of the method was from 5.0 to 100 μg/mL with a correlation coefficient (R2) of 0.999 7. The spiked recovery was in the range of 97.33%–105.74%. At the signal-to-noise ratio of 3 (RS/N = 3), the limit of detection (LOD) was 0.06 mg/100 g and the limit of quantification was 0.2 mg/100 g (RS/N = 10) for taurine. The proposed method proved to be simple and sensitive for routine analysis of taurine in milk powder with good reproducibility.

Key words: on-line automated pre-column derivatization; taurine; milk powder; ortho-phthaladehyde (OPA)

摘要： 建立以邻苯二甲醛为衍生试剂测定乳粉中牛磺酸含量的高效液相色谱方法.标准品和样品在自动进样器中完成自动衍生反应后直接进入高效液相色谱系统进行分析,方法采用Ultimate AQ-C18 (2.1 mm×100 mm,3μm)为分析色谱柱,以乙腈和10 mmol/L乙酸钠(pH 4.2)作为流动相,柱温40℃,流速0.4 mL/min.结果表明:在5～100 μg/mL范围内牛磺酸线性关系良好,回归方程为y=19.800 6x+20.176 4,相关系数为0.999 7.样品加标回收率为97.33％～105.74％.本方法最低检测限(RS/N=3)为0.06 mg/100 g,最低定量限(Rs/N=10)为0.2 mg/100 g.本方法测定乳粉中牛磺酸含量重复性好、灵敏度高,且比国标检测方法操作简单,适用于乳粉中牛磺酸的常规分析检测.

关键词: 在线自动化柱前衍生；牛磺酸；乳粉；邻苯二甲醛