不同采摘期金银花中氨基酸含量的PITC柱前衍生HPLC法测定

Determination of amino acids in Lonicera japonica of different harvesting period by HPLC with PITC pre-column derivation

目的建立柱前异硫氰酸苯酯（PITC）衍生HPLC测定金银花中水解氨基酸的方法,并比较不同采摘期对金银花氨基酸的含量影响。方法 6 mol·L-1盐酸水解金银花蛋白,以PITC为柱前衍生试剂,采用HPLC法测定不同采摘期金银花中氨基酸的峰面积并计算其含量。结果 18种氨基酸的分离良好,线性关系良好,精密度RSD在0.28%∽0.86%之间,重复性RSD在0.92%∽2.01%之间,稳定性RSD在0.67%∽1.21%之间,加样回收率96.58%∽103.52%之间且RSD均小于5%。金银花中18种氨基酸的总量、药用氨基酸合计和增味剂氨基酸合计都是幼蕾期最高,二白期次之。结论该方法简便、快捷,能准确的测定金银花氨基酸的含量。二白期氨基酸含量较佳,适合作为金银花的采收期,为山东金银花的规范化种植提供了理论依据。

Objective To establish a PITC pre-column derivation and HPLC method for amino acids in Lonicera japonica,and compare the determination of total amino acids among different harvesting periods. Methods The amino acids in Lonicera japonica were hydrolysised by 6mol·L-1hydrochloric acid. The pre-column derivating reagent was phenyl isothiocyanate（ PITC）. The content of the amino acids were determined by HPLC method. Results The method can accurately assay the 18 kinds of amino acids in Lonicera japonica. The linear relationship was good,the precision RSD were between 0. 28% and 0. 86%,the repeatability RSD was between 0. 92% and 2. 01%,the stability RSD were between 0. 67% and 1. 21%,the sample recovery was between95. 58% and 103. 52%,and the RSD were less than 5%. The contents of total amino acids,amino acids for medical purposes and flavor amino acid were maximum in young bud period and second white period secondly. Conclusion The method was very accurate,sensitive and reliable to determine the contents of amino acids in Lonicera japonica,and provided a theoretical basis for the standard cultivation of Lonicera japonica in Shandong.