Determination of soluble sugar in tea plant by HPLC-ELSD and its relationship with freezing resistance

A HPLC-ELSD method for quantification analysis of the soluble sugar in the leaves of tea plant(Camellia sinensis) was developed under the following chromatographic condition: column,Agilent Zorbax carbohydrate,4.6×250 mm,10 μm;mobile phase,acetonitrile-water(75:25,V/V);flow rate,1.0 mL/min;column temperature,30℃;sampling volume,10 μL.The temperature of drift tube was 85℃,and the nebulizer temperature was 36℃.The contents of fructose,glucose and sucrose in the leaves of four tea tree species during overwintering periods were determined with this method.The results show that the change ranges of three soluble sugars are all in the order of Wancha91 Longjing43 Pingyangtezao Wuniuzao.The soluble sugar content in the tea leaves has a regular increasing trend with decline of temperature.As the main ingredient of the soluble sugar,sucrose could be detected rapidly,simply and accurately by HPLC-ELSD.It’s a new way to determine the freezing resistance of tea plant.