NEGATIVE ELECTRODE SOLUTION OF TWO-PACK TYPE REAGENT FOR KARL-FISHER COULOMETRIC TITRATION AND TWO-PACK TYPE REAGENT CONTAINING THE NEGATIVE ELECTRODE SOLUTION

摘要

PURPOSE: A negative electrode solution of a two-pack type reagent for the Karl-Fisher coulometric titration and a two-pack type reagent containing the negative electrode solution for the determination of moisture content are provided, to reduce the manufacturing cost by employing choline chloride instead of expensive diethanolamine·HCl at a negative electrode solution. CONSTITUTION: The negative electrode solution comprises 1.5-3 mol of imidazole; 13.5-25.0 g of iodine; 63-66.5 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. The two-pack type reagent comprises 3-5 vol% of a positive electrode solution; and 100 vol% of the negative electrode solution. Preferably the positive electrode solution comprises 100-105 g of imidazole; 13-15 g of iodine; about 1-2 mol of dry sulfurous acid gas; and the balance volume of a solvent per 500 mL of the total volume. Preferably the solvent is methanol.