ASTM D7304-22a

1.1 This test method covers the chemical analysis of engine coolant for denatonium benzoate (DNB) by high-performance liquid chromatography (HPLC). DNB is added to potentially render engine coolant unpalatable to animals and humans. This analytical method was designed for the analysis of DNB and is not valid for any other bittering agents such as denatonium saccharide.

1.2 This test method is applicable to both new and used coolants.

1.3 Coelution of other ions may cause interferences in the detection of the denatonium cation. In the case of unfamiliar formulations, identification verification should be performed by either or both fortification and dilution of the sample matrix with denatonium ion.

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

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.

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.