高效液相色谱法测定汉中茶叶中茶氨酸含量

Determination of theanine in Hanzhong tea plantation by high performance liquid chromatography

中文关键词:  茶叶鲜样  茶氨酸  分析评价

英文关键词:tea fresh sample  theanine  analysis and evaluation

中文摘要:

      目的 以汉中市不同县区主栽茶叶品种鲜叶为试验材料, 系统分析汉中茶区茶叶中茶氨酸的含量, 并对其进行分析评价。方法 采用高效液相色谱法(high performance liquid chromatography, HPLC), Diamonsil C18 (46 mm×250 mm, 5 μm); 以乙酸铵和乙酸铵、甲醇、乙腈的混合溶液(乙酸铵:甲醇:乙腈=1:2:2, V:V:V)作为流动相, 流速: 1 mL/min; 柱温: 25 ℃; 检测波长为338 nm; 对不同地区不同品种的茶叶中的茶氨酸的含量进行测定。结果 方法的精密度高和重复性好。加标回收率在87.85%~96.95%之间, 相对标准偏差为2.25%。汉中茶叶茶氨酸含量总体较高, 均值可达3.55 g/100 g。宁强县种植的龙井长叶茶氨酸含量最高, 为5.3 g/100 g, 远高于群体种茶氨酸最高值4.72 g/100 g。结论 就茶氨酸而言, 不同品种茶树的差异较大, 且新引进品种优于群体种。

英文摘要:

      Objective To analyze and evaluate the content of theanine in Hanzhong green tea systematically, with the main planting of tea in different plantations as experimental materials. Methods Theanine in tea of different varieties of different regions was determined by high performance liquid chromatography (HPLC) with the following conditions: Diamonsil C18 (46 mm×250 mm, 5 μm) ammonium acetate and mixed solution of ammonium acetate, methanol, and acetonitrile (ammonium acetate: methanol: acetonitrile =1:2:2, V:V:V) as the mobile phase, flow rate 1mL/min, column temperature 25 ℃, and detection wavelength of 338 nm. Results This method was of high precision and repeatability. The spiking recovery rate was between 87.85%~96.95% and the relative standard deviation was 2.25%. The content of theanine in Hanzhong green tea was generally better and the average value was 3.55 g/100 g. Longjingchangye which planted in Ningqiang had the highest content of theanine, 5.3 g/100 g, which was higher than the highest content of native species, 4.72 g/100 g. Conclusion The content of theanine has big difference between different varieties, and the new varieties are superior than native species in terms of theanine.