Sodium carbonate anhydrous

Copper(II) sulphate pentahydrate, citric acid monohydrate, anhydrous sodium carbonate, potassium hexacyanoferrate(II) trihydrate, zinc acetate, calcium carbonate, potassium iodide, sulphuric acid, potassium thiocyanate, starch, phenolphthalein, sodium hydroxide, sodium thiosulfate and sodium chloride were purchased from Kemika (Zagreb, Croatia). Myrtenol standard was obtained from Sigma Aldrich (St. Lois, MO, USA) and C7-C30 saturated alkanes standard from Merck (Darmstadt, Germany). Helium for gas chromatography was obtained from Messer, Austria.

Solvents used for the extraction and analysis were HPLC grade, namely ethanol, formic acid and acetonitrile, purchased from BDH Prolabo (Lutterworth, UK). Distilled water was of Milli-Q quality (Millipore Corp., Bedford, NY, USA). Anhydrous sodium carbonate (≥99.5%) and sodium phosphate (96%) were obtained from Kemika (Zagreb, Croatia), Folin-Ciocalteu reagent from Merck (Darmstadt, Germany), fluorescein sodium salt from Honeywell Riedel-de-Haën (Bucharest, Romania), Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) from Acros Organics (Thermo Fisher Scientific, Geel, Belgium) and 2,2′-Azobis (2-amidinopropane) hydrochloride from Sigma-Aldrich (Steinheim, Germany).
Phenolic compounds of authentic standards of caffeic, gallic, ferulic, chlorogenic and p-coumaric acid, quercetin-3-glucoside, kaempferol-3-rutinoside and myricetin were purchased from Sigma–Aldrich (Steinheim, Germany); epicatechin, catechin, epigallocatechin gallate, epicatechin gallate, procyanidin B1, procyanidin B2, apigenin and luteolin from Extrasynthese (Genay, France); and quercetin-3-rutinoside from Acros Organics (Thermo Fisher Scientific, Geel, Belgium).

Methanol (high-performance liquid chromatography, HPLC grade), 2,2-diphenyl-1-picrylhydrazyl (DPPH), catechin, benzoic acid, hydroxytyrosol, oleuropein, homovanillyl alcohol, p-coumaric acid, pinoresinol and apigenin were purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany). Tyrosol, 3,4-dihydroxybenzoic acid, gallic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, cinnamic acid, ferulic acid, o-coumaric acid and Folin-Ciocalteu’s reagent were obtained from Fluka Chemie GmbH (Buchs, Switzerland). Formic acid (99+%) and vanillin were purchased from Acros Organics (Morris Plains, NJ, USA). Sodium hydroxide and sodium carbonate anhydrous were purchased from Kemika (Zagreb, Croatia) while sodium molibdate dehydrate, sodium nitrite, glacial acetic acid and aluminum chloride were obtained from Merck (Darmstadt, Germany).