Abstract: An electrolytic solution for Karl Fischer's coulometric titation and a method for measuring the water content of a sample using the same are disclosed. The electrolytic solution contains iodine or an iodide, sulfur dioxide, an amine and a solvent, wherein the amine is a pyridine derivative, imidazole or an imidazole derivative and the solvent is a mixture of (a) a polyhydric alcohol or an ether compound thereof, (b) methanol and (c) a halogenated hydrocarbon or an aromatic hydrocarbon. The measurement method achieves a high precision with reduced measurement time and is suitable for making water content measurements using a water content vaporization method.

Abstract: An electrolyte for Karl Fischer coulometric titration, which contains(a) iodine or an iodine compound,(b) sulfur dioxide,(c) a halogenated hydrocarbon or an aromatic hydrocarbon,and(d)(i) an amine of the following general formula (I), an amine of the following general formula (II) and a monohydric alcohol, or(ii) an amine of the following general formula (I) and/or an amine of the following general formula (II) and a polyhydric alcohol or an ether compound thereof of the following general formula (III):General formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each represent a hydrogen atom, an alkyl group, a pyridyl group or a pyrrolidinyl group;General formula (II): ##STR2## wherein R.sup.3 -R.sup.10 each represent a hydrogen atom or an alkyl group, and m is an integer of 1-5;General formula (III):R.sup.11 O--(CH.sub.2).sub.n --OR.sup.12 (III)wherein R.sup.11 and R.sup.12 each represent a hydrogen atom or an alkyl group, and n is 2 or 3.