ASTM E2679-26

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 The following applies to all specified limits in this specification: for purposes of determining conformance with this specification, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E29.

1.4 Consult current OSHA regulations, suppliers’ Safety Data Sheets, and local regulations for all materials used in this specification.

1.5 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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.

1.7 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.

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 min 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.