ASTM D2549 Separation of Representative Aromatics and Nonaromatics Fractions
ASTM D2549 Standard Test Method for Separation of Representative Aromatics and Nonaromatics Fractions of High-Boiling Oils by Elution Chromatography
1. Scope
1.1 This test method covers the separation and determination of representative aromatics and nonaromatics fractions from hydrocarbon mixtures that boil between 232 and 538°C (450 and 1000°F). Alternative procedures are provided for the separation of 2 g or 10 g of hydrocarbon mixture.

NOTE 1 - Some components may not be eluted from the chromatographic column for some types of samples under the conditions used in this method.

NOTE 2 - Test Method D 2007 is an alternative method of separating high-boiling oils into polar compounds, aromatics, and saturates fractions.

1.2 An alternative procedure is provided to handle samples boiling below 232°C (450°F), but whose 5 % point is above 178°C (350°F) as determined by Test Method D2887. This procedure is given in Appendix X1.

1.3 The values stated in acceptable SI units are to be regarded as the standard. The values given in parentheses are provided for information purposes only.

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 and heal practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents
2.1 ASTM Standards:
D2007 Test Method for Characteristic Groups in Rubber Extender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromatographic Method
D2425 Test Method for Hydrocarbon Types in Middle Distillates by Mass Spectrometry
D2786 Test Method for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions by High Ionizing Voltage Mass Spectrometry
D2887 Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography
D3239 Test Method for Aromatic Types Analysis of Gas-Oil Aromatic Fractions by High Ionizing Voltage Mass Spectrometry

3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 aromatics fraction - the portion of the sample desorbed with the polar eluants. The aromatics fraction may contain aromatics, condensed naphthenic-aromatics, aromatic olefins, and compounds containing sulfur, nitrogen, and oxygen atoms.

3.1.2 nonaromatics fraction - the portion of the sample eluted with n-pentane. The nonaromatics fraction is a mixture of paraffinic and naphthenic hydrocarbons if the sample is a straight-run material. If the sample is a cracked stock, the nonaromatics fraction will also contain aliphatic and cyclic olefins.