柱前衍生-高效液相色谱法测定肠内营养剂中18种氨基酸的含量

目的建立柱前衍生-高效液相色谱法测定肠内营养剂中18种氨基酸的含量。方法以邻苯二甲醛为衍生化试剂,Agilent C18色谱柱(150 mm×4.6 mm,5.0μm),流动相为甲醇-50 mmol.L-1醋酸钠缓冲液(pH 5.6),采用梯度洗脱,流速为1.0 mL.min-1,柱温30℃;FLD荧光检测,激发波长340 nm,发射波长460 nm。待测肠内营养剂样品经超声提取后,与衍生化试剂反应,取20μL进样分析。结果本法线性关系良好,18种氨基酸的线性回归系数范围在0.998 8～0.999 9;平均回收率在94.12%～113.73%,日间、日内精密度RSD均<10%;样品溶液在24 h内稳定。结论该法简便、灵敏、专属性强,能准确对肠内营养剂中18种氨基酸进行定量分析,适用于该类制剂的质量控制和评价。

Pre-column derivatization-HPLC method for determination of 18 amino acids in enteral nutrition

AIM To develop a pre-column derivatization-HPLC method for the determination of 18 amino acids in enteral nutrition.METHODS The derivatization reagent was O-phthalaldehyde.An Agilent C18 column(150 mm × 4.6 mm,5.0 μm)was used with a mobile phase consisting of methanol-50 mmol·L-1sodium acetate(pH 5.6)for gradient elution analysis.The flow rate was 1.0 mL·min-1.The column temperature was 30 ℃.The λex of FLD was 340 nm and the λem was 460 nm.The enteral nutrition was firstly ultrasonic extracted,then 20 μL of the sample after derivatization was injected for HPLC analysis.RESULTS The linear regression coefficients of eighteen amino acids were within the range of 0.998 8-0.999 9.The range of average recoveries was 94.12%-113.73%.Both the inter-day RSD and the intra-day RSD were less than 10%.The sample solvent was stable in 24 h.CONCLUSION The established method is simple,sensitive and specific which can be applied for determination of amino acids in enteral nutrition and quality control of the preparation.