【国外标准】 Standard Test Methods for Water in Halogenated Organic Solvents and Their Admixtures

4.1 High water concentrations can have a detrimental effect on many uses of halogenated solvents.4.1.1 Water can cause corrosion and spotting when solvents are used for metal cleaning.4.1.2 Water can reduce the shelf life of aerosol formulations.4.1.3 Water can inhibit desired reactions when solvents are used in formulations.1.1 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 ppm to 1000 ppm can be determined in these solvents. Two test methods are covered as follows:1.1.1 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.1.1.2 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.1.2 Either of these test methods can be used to determine typical water concentrations (15 ppm to 500 ppm) found in halogenated solvents.1.3 These test methods recommend the use of commercially available Karl Fischer titrators and reagents.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Sections 11 and 15.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.