【国外标准】 Standard Test Method for Water in Purified Terephthalic Acid (PTA) by Volumetric Karl Fischer Titration

4.1 The presence of water in PTA used for the production of polyester is undesirable because it reduces the purity of the PTA.4.2 Determining the amount of water content remaining from the manufacture of PTA is often required. This test method is suitable for setting product specifications and for use as an internal quality control tool where these products are produced or are used.1.1 This test method covers the determination of water in purified terephthalic acid (PTA) between 0.01 and 1.00 % (w/w) by Volumetric Karl Fischer Titration.1.2 In determining the conformance of the test results using this method to applicable specification, results shall be rounded off in accordance with the rounding-off method of Practice E29.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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.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.