茶氨酸的衍生化及毛细管电泳定量技术

Derivation of Theanine and Its Determination by Capillary Electrophoresis

采用胶束电动力学毛细管电泳技术定量茶氨酸,以2,4-二硝基氟苯为衍生化试剂,建立茶氨酸定量的新方法。运行缓冲液为pH9.8的0.03 mol/L四硼酸钠缓冲液体系,分离电压为28kV,分离温度为17℃,在360 nm下进行检测。研究了不同pH、反应时间、反应温度、缓冲液浓度对衍生化反应的影响,确立了衍生化反应的最佳条件。证实了4℃和25℃环境下衍生化产物可以稳定保存5天。测定了茶氨酸衍生化方法的性能指标:线性范围为0.2～5 mmol/L(r2=0.993),最低检测限为0.05 mmol/L。

A novel derivative method for determination of theanine was developed by micellar electrokinetic capillary chromatography (MECC). Samples were derivated with 2,4-dinitrofluorobenzen. The buffer solution used in this method was 0.03mol/L sodium borate solution (pH9.8). Column temperature was 17℃. The separating voltage was 28 kV and detection at 360 nm. Factors of pH value, reaction time, reaction temperature and concentration of buffer were optimized. The products of derivation of theanine can be stable for five days at 4℃ or 25℃. The linearity of this assay was 0.2~5 mmol/L (r2=0.993). The minimal detection limit (S/N=2) was 0.05 mmol/L.