on 05-01-201210:31 AM - edited on 10-15-202111:26 AM by Closed Account
Wilson D, Yang C. Application Note 420 Purpose:
To show a complete analytical metabolomic workflow including
(1) data acquisition using a high-resolution accurate mass instrument that is equipped with a Higher Energy Collisional Dissociation (HCD) cell and coupled to a high pressure LC (Figure 1),
(2) metabolite differential abundance analysis, and (3) structural elucidation of relevant metabolites using accurate mass and HCD fragmentation information to highlight the component differences between green and black tea.
Green and black tea extracts were analyzed using an LTQ Orbitrap XL™ with an HCD cell. Chromatography was performed using an Accela High Speed LC equipped with a 2.1 mm ID Hypersil GOLD™ column packed with 1.9 μm particles. Data Dependent™ analysis was performed using an LTQ Orbitrap XL with full scan data acquired at a resolving power of 30,000 and MSn data acquired at a resolving power of 7500 following HCD fragmentation.
The study included a comparative analysis of green and black tea using differential analysis software to identify compositional variations between the two tea samples. Using a UHPLC coupled with a small particle column afforded a fast analysis time while maintaining very high chromatographic resolution. The high mass accuracy data (better than 3 ppm with external calibration) was used to determine elemental composition and
for tentative identification of compounds via database searching. HCD fragmentation facilitated structural identification and confirmation. This was demonstrated with the example of epigallocatechin gallate (EGCG).