ASTM D3401: Standard Test Methods for Water in Halogenated Organic Solvents and Their Admixtures

These test methods describe the use of the Karl Fischer (KF) titration for determination of water in halogenated organic solvents and mixtures thereof.Water concentrations from 2 to 1000 ppm can be determined in these solvents. Two test methods are covered as follows:

Test Method A, Water Determination Using a Coulometric KF Titrator—The coulometric test method is known for its high degree of sensitivity (typically < 10 µg H₂O) and should be the test method of choice if water concentrations are typically below 50 ppm or if only small amounts of sample are available for water determinations. This test method requires the use of equipment specifically designed for coulometric titrations.

Test Method B, Water Determination Using a Volumetric KF Titrator—The volumetric test method is a more traditional approach to KF water determinations. Although titrators are specifically designed for KF volumetric determinations, many automatic titrators on the market can be adapted to perform KF titrations.

Either of these test methods can be used to determine typical water concentrations (15 to 500 ppm) found in halogenated solvents.

These test methods recommend the use of commercially available Karl Fischer titrators and reagents.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Sections 11 and 15.

coulometric Karl Fischer titration

halogenated organic solvents

Karl Fischer test method—water content

moisture