固相萃取-反相高效液相色谱法检测婴幼儿配方乳粉中叶酸的含量

目的建立了快速、灵敏的检测婴幼儿配方乳粉中叶酸含量的方法。方法使用高氯酸在超声波条件下提取配方乳粉中的叶酸,取一定量的滤液经过含有C18填料的固相萃取小柱进行除杂,再经过高锰酸钾衍生后利用反相高效液相色谱测定叶酸的含量。流动相选用pH5.0的浓度为0.1mol/L的磷酸二氢钠溶液,流动相流速为1.0ml/min,经BDSC18色谱柱进行分离(柱温为30℃)。结果方法在0.005～1.5μg/ml范围内线性良好,方法的平均回收率为91.7%～98.3%,RSD%为2.5%,检出限为0.005μg/ml,定量限为0.017μg/ml。结论应用本方法检测婴幼儿配方乳粉中的叶酸,具有操作简单、精密度高、准确度好、容易推广等优点。

DETERMINATION OF FOLIC ACID IN INFANT FORMULA MILK POWDER BY SOLID-PHASE EXTRACTION-REVERSED PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Objective A quick and sensitive method was developed for determination of folic acid (FA) in infant formula milk powder. Method Perchloric aicd was added into infant formula milk powder to extract FA in ultrasonic wave condition. After solid-phase extraction (SPE) with C18 material as plug and reaction with potassium permanganate, FA was determined by reversed phase high-performance liquid chromatography (RP-HPLC). pH 5.0 and 0.1 mol/L sodium dihydrogen phosphate were used as mobile phase. the flow rate was 1 ml/min. BDS C18 was used as separating column and column temperature was 30 ℃. Results The linear range of the method was 0.005-1.5 μg/ml. The average recovery was 91.7%- 98.3%. The relative standard deviation (RSD) was 2.5%. The limit of detection was 0.005 μg/ml, and the limit of quantification was 0.017 μg/ml. Conclusion The method has following advantages: simple, precise, accurate and easy to practice.