Geographical Classification of Green Teas Based on MEKC with Laser-Induced Fluorescence Detection

A chromatographic analysis of green tea leaves from different tea-producing areas in Zhejiang province was performed by micellar electrokinetic chromatography coupled with laser-induced fluorescence detector. An electrolyte containing 100 mM borate (pH 9.8) and 20 mM sodium dodecylsulfate was used as the running buffer. The tea infusions were injected for 5 s with a pressure of 0.5 psi. A fused-silica capillary with an internal diameter of 75 μm and a total length of 60 cm was used. Based on the laser induced-native fluorescence profiling, green tea samples from different areas in Zhejiang province were classified by cluster analysis.