高效液相色谱法测定强化食品中维生素C的含量

建立了强化食品(饮料、奶粉、含乳饮料、大米、果泥及果冻)中维生素C含量的高效液相色谱检测方法。优化了样品处理方法,在水浴控温和避光条件下处理样品,避免维生素C被氧化。选用Tech Mate C18–ST(250 mm×4.6 mm,5μm)反相色谱柱,以0.05 mol/L磷酸二氢钾缓冲溶液(p H 3)为流动相,流量为1.0m L/min,检测器为光电二极管阵列检测器,检测波长为266 nm。线性范围为0.2~100μg/m L,相关系数为0.999 6,果泥中维生素C的定量限为20 mg/kg,其它为100 mg/kg,加标回收率为82.2%~107%,测定结果的相对标准偏差为1.23%~6.86%(n=8)。该方法简单快速,其灵敏度、准确度和精密度均能满足强化食品中维生素C的检测要求。

Determination of Vitamin C Content in Fortified Foods by HPLC

A method for determination of vitamin C （Vc） in fortified foods （juice, milk power, milk drinks, rice, puree and jelly） by high performance liquid chromatography （HPLC） was established. The sample processing method was optimized by controlling the water bath tempertature and keeping in dark conditions to avoid oxidation of vitamin C. The samples were analyzed using 0.05 mol/L potassium dihydrogen phosphate buffer solution （pH 3） as mobile phase with the flow rate of 1.0 mL/min, and detected by means of photodiode array detector with the detection wavelength 266 nm. A good linear relationship was shown at the range of 0.2-100 μ g/mL with the linear correlation coefficient of 0.999 6, and the detection limits were 100 mg/kg （20 mg/kg for puree）. The recoveries were 82.2%-107%, and the relative standard deviation of determination results was 1.23%-6.86%（n=8）. This method had the advantage of easy sample handling, high sensitivity and precision, which can meet the requirements of the determination of vitamin C in fortified foods.