高效液相钴离子催化化学发光抑制法测定茶叶中的茶氨酸

 研究了用高效液相分离、抑制化学发光测定茶叶中茶氨酸的分析方法。该法采用YWG C18(10μm,250mm×5 0mmi d )柱,以0 01mol·L-1醋酸钠 醋酸缓冲液(pH5 5)为流动相,流速为0 8mL·min-1。对茶氨酸抑制Co2+催化鲁米诺(luminol)与过氧化氢(H2O2)化学发光反应的条件进行了优化:Co2+的质量浓度为2μg·L-1,鲁米诺浓度为0 25mmol·L-1,H2O2浓度为0 5mmol·L-1。在茶氨酸的质量浓度为0 2g·L-1～5 0g·L-1时,茶氨酸抑制化学发光产生负峰的相对峰面积Y(将实际峰面积缩小至万分之一)与其质量浓度X(kg·L-1)的线性回归方程为Y=33862X+1 0605(r=0 9983)。

Determination of Theanine in Tea Leaves by HPLC-Inhibited Chemiluminescence with Co2+ Catalyst

A method for the separation and determination of theanine in tea leaves has been developed, based on inhibited chemiluminescence of cobalt-catalyzed luminol-H2O2 reaction by theanine. Separations were performed on a YWG-C18 column using a mobile phase of 0.01 mol.L-1 sodium acetate-acetic acid buffer at pH 5.5 at a flow rate of 0.8 mL.min-1. The optimum concentrations of Co2+, luminol, and H2O2 were 2 micrograms.L-1, 0.25 mmol.L-1, and 0.5 mmol.L-1, respectively. Under the conditions mentioned above, the relative peak area (Y) of inhibited chemiluminescence of theanine was linear with the concentration (X) of theanine in the range of 0.2 g.L-1-5.0 g.L-1 and its linear regression equation was Y = 33,862 x + 1.0605 (r = 0.9983). The average recovery was 97.82% with a RSD of 2.16%.