摘要
建立一种可适用于不同品种的茶及茶叶制品中茶氨酸含量的高效液相色谱法。特点是通过在传统流动相中添加离子对试剂(1-癸烷磺酸钠),以改进不同加工方式的茶叶中茶氨酸测定过程中极性强、保留差、抗干扰能力弱等问题。流动相:0.005 mol/L癸烷磺酸钠水溶液(含0.05%三氟乙酸)∶乙腈=75∶25(v/v),色谱柱:C18(5μm,250×4.6 mm),流速:1.0 m L/min,检测波长:203 nm,柱温:35℃,进样体积:10μL。茶氨酸在0.05 mg/m L到0.50 mg/m L范围内呈现良好的线性关系,检出限为1.996 ng,定量限为7.984 ng,回收率为102.2%,精密度为0.7%。本方法适用于多品种茶叶中茶氨酸含量的测定,操作简便,分离快速,结果准确。
L- theanine（ L-theanine,γ- glutamylethylamide）,belonging to the amide（ N- ethyl-r- glutamine）,easily soluble in water,is a kind of peculiar non-protein amino acid. It is a common content that directly affects the quality and taste of tea,can relieve the bitter tea taste. Theanine has many beneficial effects,such as the effect of central nervous system has been fully studied,also the role of lowering blood pressure and anti tumor effect etc.. However,fast detection method for the level of L-theanine in tea is not available for now. Based on the above reasons,a RP-HPLC method for the determination of L-theanine was set up,and detailed by adding ion pair reagent（ 1-decane sodium sulfonate） into the traditional RP mobile phase. Mobile Phase： 0. 005 mol / L Sodium 1-Decanesulfonate solution with 0. 05% TFA and 15 ~ 30% acetonitrile; the column： C18（ 5 μm,250 ×4. 6 mm）; flow rate： 1. 0 ml / min; detective wavelength： 203 nm; column temperature： 35 ℃,injection volume：10 μ L. The range of L- theanine linear relationship is 0. 05 mg / m L to 0. 50 mg / m L,y = 1. 13 × 10^7 x ＋ 2. 21 ×104,R2= 0. 9999. S / N = 3,the minimum detectable concentration limit was 1. 996 ng. S / N = 10,the quantification limit was 7. 984 ng. The method recovery is 94. 9% and 102. 2%,and the precision is 0. 7%. Theestablished method is simple,rapid,accurate,and multiple suitable for theanine analysis in tea.
出处
《北京联合大学学报》
CAS
2016年第2期83-87,共5页
Journal of Beijing Union University
基金
国家自然科学基金面上项目(31471587)
北京市教委科技发展面上项目(KM201311417013)
