选取白茶为原料,比较了2种HPLC方法测定茶叶中茶氨酸含量,即不经衍生的三氟乙酸洗脱法和经邻苯二甲醛(OPA)柱前衍生的国标法(GB/T 23193-2008)在茶氨酸含量测定上的数值差异。结果显示:以Wa-ters AccQ.Tag化学试剂包的测定结果作为参照,三氟乙酸洗脱法测定结果与AccQ-Tag试剂盒法的测定结果比较接近,而GB/T 23193-2008测定结果与AccQ-Tag试剂盒测定结果在5%的显著水平上差异显著。在此基础上,对GB/T 23193-2008法中的OPA衍生化反应时间进行了实验论证,发现在338 nm检测波长下,衍生化产物在衍生后15～20 min内最稳定且具有最大信号响应值。

In this paper,HPLC eluting with trifluoroacetic acid(TFA) solution for theanine determination in white tea was compared to the national standard HPLC method(GB/T 23193-2008) with the pre-column derivation by o-phthaldialdehyde(OPA).The reference was Waters AccQ-Tag Kit.The results showed that theanine contents detected by HPLC method with TFA elution are more close to Waters AccQ-Tag kit,while GB/T 23293-2008 method had significant differences in a significant level of 5% compared to Waters AccQ-Tag kit.Furthermore,the derivative reaction time of GB/T 23193-2008 was investigated.It is found that the derivative products were stable in 15~20 minutes after OPA derivation and had a maximum response signal at 338nm.