ASTM D7676-23 PDF

SIGNIFICANCE AND USE 5.1 Low operating temperature fuel cells such as proton exchange membrane fuel cells require high purity hydrogen for maximum material performance and lifetime. Analysis to at least 0.05 µmol/mol concentration of total halogenated (measured as methyl fluoride) in hydrogen is necessary for assuring a feed gas of sufficient purity to satisfy fuel cell system needs as defined in ISO 14687, SAE J2719, and the California Code of Regulations, or as specified in regulatory codes. 5.2 Although not intended for application to gases other than hydrogen, techniques within this screening method can be applied to other gaseous samples requiring total halogenated hydrocarbon content determination. The method must be validated when used to test fuels or other gaseous samples that may contain interfering compounds. SCOPE 1.1 This practice covers the screening of organic halide content of gaseous fuels using electron capture detection. Although primarily intended for determining organic halides in hydrogen used as a fuel for fuel cell or internal combustion engine powered vehicles, this screening method can also be used, if qualified, to measure organic halides in other gaseous fuels and gaseous matrices. 1.2 The procedure described in this method was designed to screen organic halides in hydrogen to a level much less than required by SAE J2719 and the California Code of Regulations, Title 4, Division 9, Chapter 6, Article 8, Sections 4180 – 4181. It will yield false positive result to other compounds that show response to the electron capture detector (ECD). Samples that do not pass the criteria of this screening process shall be tested to quantify and qualify the contaminants using Test Method D7892. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered 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.