柱前衍生化HPLC法检测紫苏子和紫苏叶中氨基酸的含量

目的：研究紫苏子和紫苏叶中游离和水解氨基酸的种类及含量。方法：采用柱前衍生化高效液相色谱法检测，以异硫氰酸苯酯为衍生试剂，使用Ultimate Amino Acid氨基酸分析柱（4.6 mm×250 mm，5 μm），流动相A为乙腈-水（80：20），流动相B为醋酸钠缓冲液（pH 6.5）-乙腈（93：7），流速1.0 mL·min^-1，检测波长254 nm。结果：21种氨基酸均呈现良好的线性关系（R²>0.999 0），紫苏子和紫苏叶中水解氨基酸的平均回收率分别为93.21%~101.6%（RSD为0.87%~2.9%，n=6）和96.88%~100.8%（RSD为0.68%~2.7%，n=6）。紫苏子中检测到17种游离氨基酸，含8种人体必需氨基酸；紫苏叶中检测到18种游离氨基酸，含7种人体必需氨基酸，且紫苏叶中氨基酸含量高于紫苏子。结论：本法可用于紫苏中氨基酸的含量测定。

Objective:To investigate the varieties and contents of free and hydrolyzed amino acids in Perillae Fructus and Perillae Folium.Methods:HPLC with pre-column derivatization was employed,with phenyl isothiocyanate(PITC)as derivatization reagent.Separation was performed on an Ultimate Amino Acid specified column(4.6 mm×250 mm,5 μm)and the mobile phase consisted of acetonitrile-water(80:20)and sodium acetate(pH 6.5)-acetonitrile(93:7)at a flow rate of 1.0 mL·min^-1.The detection wavelength was set at 254 nm.Results:The calibration curves of 21 kinds of amino acids showed good linearity within their test ranges.And the average recovery rates of the hydrolyzed amino acids in Perillae Fructus and Perillae Folium ranged from 93.21% to 101.6%(RSD 0.87%-2.9%,n=6)and 96.88%-100.8%(RSD 0.68%-2.7%,n=6),respectively.17 Kinds of amino acid were detected in Perillae Fructus,8 of which were essential amino acid.18 Kinds of amino acid were detected in Perillae Folium,7 of which were essential amino acid.The amino acid contents in Perillae Folium were higher than those in Perillae Fructus.Conclusion:The method could be used in the determination of amino acids in Perilla frutescens(L.)Britt.