Methods of Testing Petroleum and Associated Products -Standard Test Method for the Determination of Aromatic Hydrocarbons by Their Ring Number in Petroleum Middle Distillates by Supercritical Fluid Chromatography

1.1 This method provides for the determination of the mass percentage of saturates, monoaromatics, diaromatics and polyaromatics in petroleum fractions that distil below 385°C. The distillates should consist primarily of hydrocarbons and should not contain significant amounts of heteroatoms such as nitrogen, sulphur and oxygen. This method does not apply to samples that contain olefins. Olefins elute primarily in the saturate region but not exclusively, therefore any olefins in the samples will introduce a bias.

1.2 This test method utilizes supercritical fluid chromatography (SFC) for the separation of hydrocarbons and flame ionization detection (FID) for quantitative analysis.

1.3 This test method is applicable to petroleum fractions in the boiling range of 25 to 385°C, including those with dark coloration.

1.4 Saturates are initially separated from the aromatics and the aromatics are then further fractionated, according to number of aromatic rings, on a packed silica column.

1.5 The testing and evaluation of a product against this method may require the use of materials and/or equipment that could be hazardous. This document does not purport to address all the safety aspects associated with its use. Anyone using this method has the responsibility to consult the appropriate authorities and to establish appropriate health and safety practices in conjunction with any applicable regulatory requirements prior to its use.