ASTM D6379 Standard Test Method for Determination of Aromatic Hydrocarbon Types
ASTM D6379 Standard Test Method for Determination of Aromatic Hydrocarbon Types in Aviation Fuels and Petroleum Distillates - High Performance Liquid Chromatography Method with Refractive Index Detection
1. Scope
1.1 This test method covers a high performance liquid chromatographic test method for the determination of mono-aromatic and di-aromatic hydrocarbon contents in aviation kerosines and petroleum distillates boiling in the range from 50 to 300°C, such as Jet A or Jet A-1 fuels. The total aromatic content is calculated from the sum of the individual aromatic hydrocarbon-types.

NOTE 1 - Samples with a final boiling point greater than 300°C that contain tri-aromatic and higher polycyclic aromatic compounds are not determined by this test method and should be analyzed by Test Method D6591 or other suitable equivalent test methods.

1.2 This test method is calibrated for distillates containing from 10 to 25 % m/m mono-aromatic hydrocarbons and from 0 to 7 % m/m di-aromatic hydrocarbons.

1.3 The precision of this test method has been established for kerosine boiling range distillates containing from 10 to 25 % m/m mono-aromatic hydrocarbons and from 0 to 7 % m/m di-aromatic hydrocarbons.

1.4 Compounds containing sulfur, nitrogen, and oxygen are possible interferents. Mono-alkenes do not interfere, but conjugated di- and poly-alkenes, if present, are possible interferents.

1.5 This standard does not purport to address the safety concerns, 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.

2. Referenced Documents
2.1 ASTM Standards:
D4052 Test Method for Density and Relative Density of Liquids by Digital Density Meter
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6591 Test Method for Determination of Aromatic Hydrocarbon Types in Middle Distillates - High Performance Liquid Chromatography Method with Refractive Index Detection

2.2 Energy Institute Standards:
IP 436 Test Method for Determination of Automatic Hydrocarbon Types in Aviation Fuels and Petroleum Distillates - High Performance Liquid Chromatography Method with Refractive Index

3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 di-aromatic hydrocarbons (DAHs), n - compounds that have a longer retention time on the specified polar column than the MAHs.

3.1.2 mono-aromatichydrocarbons(MAHs), n - compounds that have a longer retention time on the specified polar column than the non-aromatic hydrocarbons but a shorter retention time than the di-aromatic hydrocarbons.

3.1.3 non-aromatic hydrocarbons, n - compounds that have a shorter retention time on the specified polar column than the mono-aromatic hydrocarbons.

3.1.4 total aromatic hydrocarbons, n - sum of the MAHs and DAHs.

NOTE 2 - The elution characteristics of aromatic and non-aromatic compounds on the specified polar column have not been specifically determined for this test method. Published and unpublished data indicate the major constituents for each hydrocarbon type as follows: (1) Non-aromatic hydrocarbons: acyclic and cyclic alkanes (paraffins and naphthenes), mono-alkenes (if present). (2) MAHs: benzenes, tetralins, indanes, thiophenes, conjugated poly-alkenes. (3) DAHs: naphthalenes, biphenyls, indenes, fluorenes, acenaphthenes, benzothiophenes.