A knowledge of the hydrocarbon composition of process streams and petroleum products boiling within the range of 400 to 650°F (204 to 343°C) 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.

1.1 This test method covers an analytical scheme using the mass spectrometer to determine the hydrocarbon types present in virgin middle distillates 204 to 343°C (400 to 650°F) boiling range, 5 to 95 volume % as determined by Test Method D86. Samples with average carbon number value of paraffins between C₁₂ and C₁₆ and containing paraffins from C₁₀ and C₁₈ can be analyzed. Eleven hydrocarbon types are determined. These include: paraffins, noncondensed cycloparaffins, condensed dicycloparaffins, condensed tricycloparaffins, alkylbenzenes, indans or tetralins, or both, C_nH_2n-10 (indenes, etc.), naphthalenes, C_nH_2n-14 (acenaphthenes, etc.),
C_nH_2n-16 (acenaphthylenes, etc.), and tricyclic aromatics.

Note 1—This test method was developed on Consolidated Electrodynamics Corporation Type 103 Mass Spectrometers.

1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.

1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific warning statement, see 10.1.