ASTM D2425-21

5.1?A knowledge of the hydrocarbon composition of process streams and petroleum products boiling within the range of 160 ?C to 343 ?C (320 ?F to 650 ?F) is useful in following the effect of changes in process variables, diagnosing the source of plant upsets, and in evaluating the effect of changes in composition on product performance properties.

5.2?A test method to determine total cycloparafins and low level aromatic content is necessary to meet specifications for aviation turbine fuel containing synthesized hydrocarbons.

1.1?This test method covers an analytical scheme using the mass spectrometer to determine the hydrocarbon types present in conventional and synthesized hydrocarbons that have a boiling range of 160 ?C to 343 ?C (320 ?F to 650 ?F), 5 % to 95 % by volume as determined by Test Method D86. Samples with average carbon number value of paraffins between C₁₂ and C₁₆ and containing paraffins from C_{Note 1:?This test method was developed on Consolidated Electrodynamics Corporation Type 103 Mass Spectrometers. Operating parameters for users with a Quadrupole Mass Spectrometer are provided.}

1.2?This test method is intended for use with full boiling range products that contain no significant olefin content.

Biodiesel (FAME components) could interfere with the separation of the sample and the characteristic mass fragments of FAME compounds are not defined in the procedure.

Hydrocarbons containing tertiary carbon fragments, sometimes found in synthetic aviation fuels, will interfere with the characteristic mass fragments of paraffins and result in a false, elevated cycloparaffin content.

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.