ASTM D2789 Test Method for Hydrocarbon Types in Low Olefinic Gasoline by Mass Spectrometry
4. Summary of Test Method
4.1 Samples are analyzed by mass spectrometry, based on the summation of characteristic mass fragments, to determine the concentration of the hydrocarbon types. The average number of carbon atoms of the sample is estimated from spectral data. Calculations are made from calibration data which are dependent upon the average number of carbon atoms of the sample. Results are expressed in liquid volume percent.
5. Significance and Use
5.1 A knowledge of the hydrocarbon composition of gasoline process streams, blending stocks and finished motor fuels is useful in following the effect of changes in plant operating conditions, diagnosing process upsets, blending finished products and in evaluating the relationship between composition and performance properties.
