Ethanol was purchased from Fluka Biochemika (Buchs, Switzerland). Analytic HPLC grade solvents, methanol, and formic acid were purchased from Sigma Aldrich and Fluka Biochemika, respectively; potassium dihydrogen phosphate, ammonium dihydrogen phosphate, and phosphoric acid were also purchased from Sigma Aldrich.
Milli -Q ultrapure water was produced by using Sartorius Stedium Biotech mod. Arium (Sartorius, Goettingen, Germany).
Cetyltrimethylammonium bromide (cetrimide) was purchased from Extrasynthése (Genay, France), while 1,2-phenylenediamine dihydrochloride (OPDA) was purchased from Sigma Aldrich.
All polyphenolic and terpenic standards were purchased from Sigma Aldrich. Organic acids were purchased from Fluka Biochemika, while ascorbic acid and dehydroascorbic acid were purchased from Extrasynthése.