LC-MS Analysis of Polyphenols in Green Tea

Instrumental: Orbitrap Discovery hybrid FT mass spectrometer coupled with Accela UPLC (Thermo Scientific). The mass spectrometer was operated in positive and negative ESI modes using scan and MSn options. Chromatographic separations were carried out using Gemini Hexyl-Phenyl column (2.1×150 mm, 3µ particle size, Phenomenex) using linear gradients of acetonitrile/water (with 0.1% AcOH).