柱前衍生法测定功能性饮料与口服液中的牛磺酸

Determination of Taurine in Energy Drinks and Oral Liquids by Pre-column Derivatization

采用丹磺酰氯柱前衍生法检测功能性饮料和口服液中的牛磺酸的含量,使用高效液相色谱(high performance liquid chromatography,HPLC)分析衍生产物,其中色谱配有可变波长紫外检测器,检测器波长设为254 nm。选用C18色谱柱进行产物分离,流动相选用乙酸钠水溶液-乙腈(30∶70,体积比)等度洗脱,柱温设为25℃,样品进样量为5μL。检测结果表明牛磺酸浓度为5μg/mL～50μg/L时,牛磺酸衍生物峰面积对浓度呈现良好的线性关系,相关系数为0.999。采用单因素和正交试验相结合的方法确定了最佳反应条件。结果表明衍生温度35℃,衍生时间35 min,衍生剂用量300μL,衍生溶液pH 9.5时,衍生物峰面积达到最大。在此试验条件下6组重复性试验衍生物峰面积相对标准偏差(relative standard deviation,RSD)为1.4%,重复性较好。对功能性饮料和口服液中牛磺酸进行检测,测量值与标识值误差在-10.0%～+10.0%,样品加标回收率为90.0%～108.0%,样品平行测试的偏差小于3.0%,此种方法反应条件温和,操作简单。

Taurine in energy drinks and oral liquid was determined by pre-column derivatization with dansyl chloride. The derivatives were detected by high performance liquid chromatography(HPLC). HPLC with variable wavelength detector was selected, and the wavelength was set at 254 nm. C18 column was used to separate the derivatives, and the sodium acetate solution and acetonitrile (30 ∶ 70, volume ratio) was used as mobile phase for isometric elution. The column temperature was set at 25 ℃ and the sample injection volume was 5 μL. When the concentration of taurine was 5 μg/mL-50 μg/L, the peak area of taurine derivatives had a good linear relationship with the concentration and the correlation coefficient was 0.999. The combination of single factor and orthogonal experiment was used to optimize the derivatization experiment conditions. The results of the test had shown that the peak area of the derivative reached the maximum when derivatization temperature was 35 ℃, derivatization time was 35 min, the volume of derivatization reagent was 300 μL and the pH value of the derivative solution was 9.5. Under the experimental conditions, the relative standard deviation (RSD) of the peak area of the six groups was 1.4 % and the repeatability was good. The content of taurine in energy drinks and oral liquid was detected, and the recovery rate was 90.0 %-108.0 %. The deviation between the measured value and the identified value was -10.0 %-+10.0 %, the deviation of the parallel test is less than 3.0 %. Therefore, this method had the advantages of easy preparation and mild reaction conditions.