高效液相色谱法测定茶叶中五种水溶性维生素

Determination of Five Water-Soluble Vitamins in Tea by High Performance Liquid Chromatography

用高效液相色谱（HPLC）梯度洗脱法测定茶叶中的5种水溶性维生素成分和含量,结果表明,样品经XDB-C18柱分离,使用紫外检测器（波长266 nm）,流动相为甲醇与0.03 mol/L KH2PO（4pH=6.1）混合,梯度洗脱,样品中5种水溶性维生素得到良好分离,该5种水溶性维生素标准曲线相关系数均达0.999 0以上,平均回收率为84.5%~102.7%,变异系数RSD〈5.4%。测得普洱茶中VC的含量为14.37 mg/100g,VB1的含量为2.17 mg/100 g,VB6的含量为1.58 mg/100 g,VB2的含量为3.47 mg/100 g,叶酸含量为1.34 mg/100 g;信阳毛尖中VC的含量为11.69 mg/100 g,VB6的含量为1.76 mg/100 g,VB2的含量为8.12 mg/100 g,叶酸含量为9.66 mg/100 g,未检出VB1。

A HPLC gradient elution method with UV detector was established to determine five Water-Soluble Vitamins in the tea. The optimized conditions as follows： XDB-C18 column with methanol and 0.03 mol/L KH2PO4 buffer （pH =6.1） as mobile phase, and gradient elution, detector wavelength was 266 nm. The correlation coefficients were more than 0.999 0. The recoveries were 84.5 %-102.7 %, RSD〈5.4 %. For vitamins C, B1, B2, B6 and Folic Acid, the contents were found to be 14.37 mg/100 g, 2.17 mg/100 g, 3.47 mg/100 g, 1.58 mg/100 g and 1.34 rag/100 g in Puer tea; for Maojian tea, the contents of vitamins C, B2, B6 and Folie Acid were 11.69 mg/100 g, 8.12 mg/100 g, 1.76m g/100 g, 9.66 mg/100 g, respectively. While vitamin B1 was not discovered in Maojian tea.