ASTM D2786 for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions
ASTM D2786 Standard Test Method for Hydrocarbon Types Analysis of Gas-Oil Saturates Fractions by High Ionizing Voltage Mass Spectrometry
4. Summary of Test Method
4.1 The relative abundance of alkanes (0-ring), 1-ring, 2-ring, 3-ring, 4-ring, 5-ring, and 6-ring naphthenes in petroleum saturate fractions is determined by mass spectrometry using a summation of mass fragment groups most characteristic of each molecular type. Calculations are carried out by the use of inverted matrices (derived from ion intensity calibration sensitivities) that are specific for any average carbon number. The saturate fraction is obtained by liquid elution chromatography, see Test Method D2549.
5. Significance and Use
5.1 A knowledge of the hydrocarbon composition of process streams and petroleum products boiling within the range of 205 to 540°C (400 to 1000°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 This test method, when used together with Test Method D3239, provides a detailed analysis of the hydrocarbon composition of such materials.
