【国外标准】 Standard Test Method for Acidity in Mono-, Di-, Tri- and Tetraethylene Glycol by Non-Aqueous Potentiometric Titration

5.1 This test method provides for the quantitative determination of total acidity in ethylene glycols by non-aqueous potentiometric titration. The run time for titration of ethylene glycol samples ranges from 5 to 10 min with no sample preparation required. The length of time for a titration depends on the amount of acidity in the sample and the acidity generally increases from monoethylene glycol to the higher glycols like tetraethylene glycol.5.2 Acceptable levels of acidity in ethylene glycols vary with the manufacturer’s specifications but are normally below 200 mg/kg. Knowledge of the acidity in ethylene glycols is required to establish whether the product quality meets specification requirements.1.1 This test method covers the determination of total acidity as acetic acid in commonly available grades of monoethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol using a non-aqueous potentiometric titration. This test method is useful for determining low levels of acidity, below 200 mg/kg.1.2 The mono-, di-, tri- and tetraethylene glycols can be analyzed directly by this test method without any sample preparation.1.3 Review the current appropriate Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety precautions.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 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. Specific hazards statements are given in the section on Hazards, Section 9.1.6 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.