Bio-oil water content

Karl Fisher titration has been employed for the determination of bio-oil water content. The analysis is carried out using a Metrohm Omnis KF Titrator, using Aquastar Merck two-component solution (methanol and imidazole) as a solvent and Titrant 5 Aquastar Merck two-component titrant. 1 mL of the specific titrant used reacts with 5 mg of H2O, revealing the amount of water in the sample. For each analysis, a quantity of sample (pure bio-oil or bio-oil diluted in acetone) between 40 and 100 mg is injected into the titrator. For samples diluted in acetone, the amount of water calculated through titration is adjusted according to the sample dilution level and the measured amount of water in pure acetone (0.5 wt. %).