在线柱前衍生高效液相色谱法测定古树红茶中的γ-氨基丁酸

Determination of γ-aminobutyric acid in ancient tree black tea by high performance liquid chromatography with online pre-column derivatization

目的建立在线柱前衍生高效液相色谱法(high performance liquid chromatography,HPLC)测定古树红茶中的γ-氨基丁酸的方法。方法样品在85℃水浴中浸提2 h,石墨化炭黑(graphitizing of carbon black,GCB)净化,经自动在线柱前衍生后,用Agilent ZORBAX SB-C18(250 mm×4.6 mm,5μm)色谱柱分离,用紫外检测器于338 nm波长处进行测定。结果γ-氨基丁酸在2~80μg/m L范围内线性关系良好(r=0.9994),回归方程为Y=10.224X-17.534,加标平均回收率为95.2%~96.8%,相对标准偏差为1.7%~2.9%(n=3)。结论此方法具有良好的精密度、稳定性及回收率,可用于古树红茶中的γ-氨基丁酸测定。

Objective To establish the method for determination of γ-aminobutyric acid in ancient tree black tea by high performance liquid chromatography（HPLC） with online derivatization. Methods Samples were extracted in 85 ℃ water for 2 h and refined by graphitizing of carbon black（GCB）. After derivated by automatic online column and separated by Agilent ZORBAX SB-C18（250 mm×4.6 mm, 5 μm）, the samples were measured by ultraviolet absorption detector at 338 nm. Results γ-aminobutyric acid had a good linearity in the range of 2-80 μg/m L with a correlation coefficient of 0.9994, the regression equation was Y=10.224 X-17.534, the recoveries of formaldehyde were in the range of 95.2%-96.8%, and the relative standard deviations were in the range of 1.7%-2.9%（n=3）. Conclusion This method has the advantages of good precision, stability and high recovery, which is suitable for the determination of γ-aminobutyric acid in ancient tree black tea.