Myricetin, apigenin, genistein, naringenin, catechin, baicalin and hesperetin were purchased from Merck Sigma-Aldrich (Fontenay-sous-Bois, 94120, France). Gallic acid, quercetin, rutin, hesperidin, luteolin, kaempferol, quercetin-3-O-β-d -glucoside and apigenin-7-glucoside were purchased from LGC Standards (Molsheim, 67120, France). Stock solutions of 500 µg.ml−1 were prepared for every flavonoid standard in pure MeOH and stored at −20 °C. Samples of Salicornia europaea were obtained from Terre Saline (Charente-Maritime, 1700, France). A sample of grape seed powder (Vitis vinifera) was obtained from Joli’essence (La Roque d’Anthéron, 13640, France) and used as model sample for method development. Salicornia europaea samples were carefully washed three times with water, freeze-dried and ground into powder.
Methanol and acetonitrile were LC-MS-grade and purchased from Honeywell (Morris Plains, NJ, USA). Ammonium acetate, acetic acid and deuterium were LC-MS-grade and were purchased from Sigma Aldrich (L’Isle D’Abeau Chesnes, 38080, France). Ultrapure water was obtained from a Direct-Q 3 UV (Merck, Fontenay-sous-Bois, 94120, France).
Methanol and acetonitrile were LC-MS-grade and purchased from Honeywell (Morris Plains, NJ, USA). Ammonium acetate, acetic acid and deuterium were LC-MS-grade and were purchased from Sigma Aldrich (L’Isle D’Abeau Chesnes, 38080, France). Ultrapure water was obtained from a Direct-Q 3 UV (Merck, Fontenay-sous-Bois, 94120, France).