Chemicals
Acetonitrile, methanol, hexane, and formic acid were either
HPLC grade or analytic grade purchased from Thermal Fisher Scientific
(Suwanee, GA). Water used in all preparation and analysis was
purified through Barnstead E-Pure Deionization System (Dubuque,
IA) and filtered using Millipore 0.45 lm membrane (Bedford, MA).
Standards of cyanidin-3,5-diglucoside was obtained from Sigma–
Aldrich (St. Louis, MO).
2