ONE-PACK TYPE REAGENT FOR KARL-FISHER COULOMETRIC TITRATION

摘要

PURPOSE: A one-pack type reagent for the Karl-Fisher coulometric titration is provided, to determine the moisture content of a solid sample with excellent precision and reproducibility by the Karl-Fisher coulometric titration. CONSTITUTION: The one-pack type reagent comprises 1.5-3 mol of imidazole; 13.5-24.4 g of iodine; 63.2-69.0 g of choline chloride; about 1-2 mol of dry sulfurous acid gas; and the balance volume of a solvent per 1,000 mL of the total volume. Preferably the solvent is methanol. Also the one-pack type reagent comprises 1.5-3 mol of imidazole; 13.5-24.0 g of iodine; 63.2-69.0 g of choline chloride; about 1-2 mol of dry sulfurous acid gas; and the balance volume of a solvent per 1,000 mL of the total volume. Preferably the solvent is a mixture of chloroform and methanol in the ratio of 65-70 : 30-35 by volume.