Exil sa 67120

The curcumin sample (derived from Curcuma longa, assayed for a curcuminoid content of ≥65%), the reference standard of curcumin (purity > 99.5%), potassium bromide, 2,2-diphenyl-1-picrylhydrazyl, iron (III) chloride hexahydrate, 2,4,6-Tri(2-pyridyl)-s-triazine, neocuproine, potassium persulfate, and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) were acquired from Merck (Warsaw, Poland). An analytical amount of ammonium acetate, weighed, along with hydrochloric acid 0.1 N and methanol, was supplied by Chempur (Piekary Śląskie, Poland). Copper (II) chloride dihydrate, acetic acid (99.5%), ethanol (96%), sodium acetate trihydrate, glacial acetic acid, and formic acid were supplied by Avantor Performance Materials Poland S.A. (Gliwice, Poland). Acetonitrile of an HPLC grade was supplied by Romil (Waterbeach, Cambridgeshire, UK). High-quality pure water was prepared using a Direct-Q 3 UV purification system (Millipore, Molsheim, France, model Exil SA 67120).

n-Hexane (VWR-Chemicals, Fontenay-sous-Bois cedex, France). Other chemicals and solvents (Merck, Darmstadt, Germany). High quality pure water (Exil SA 67120, Millipore, Molsheim, France).

A total of 0.1 M HCl was obtained from the analytical weighed amount in accordance with the BASF SE recommendations. Phosphate buffer at pH 6.8 was prepared according to the following description: in a 1000 mL volumetric flask, we placed 250 mL of 0.2 N potassium dihydrogen phosphate solution, then added 112 mL of 0.2 N sodium hydroxide solution and filled the mixture up to 1000 mL with distilled water. High-quality pure water was prepared using a Direct-Q 3 UV purification system (Millipore, Molsheim, France, model Exil SA 67120).