ASTM D6839 for Hydrocarbon Types, Oxygenated Compounds and Benzene
ASTM D6839 Standard Test Method for Hydrocarbon Types, Oxygenated Compounds and Benzene in Spark Ignition Engine Fuels by Gas Chromatography
13. Report
13.1 Report the mass % and liquid volume % for each oxygenate and hydrocarbon group type to the nearest 0.1 % as listed in Table 8 and report the mass % and liquid volume % for individual carbon number components to the nearest 0.01 %.
13.1.1 Calculate the total for the saturates by summation of the C5 to C10 naphthenes, the C3 to C10 paraffins, the poly-naphthenes and the C11+ saturates.
13.1.2 Calculate the total for the olefins by summation of the C5 to C10 cyclic olefins and the C3 to C10 mono and diolefins.
13.1.3 Calculate the total for the aromatics by summation of the C6 to C10 aromatics and the C11+ aromatics.
14. Precision and Bias
14.1 Precision - The precision of any individual measurement resulting from the application of this test method depends on several factors related to the individual or group of components including the volatility, concentration, and degree to which the component or group of components is resolved from closely eluting components or groups of components. As it is not practical to determine the precision of measurement for every component or group of components at different levels of concentration separated by this test method, Tables 9 and 10 present the repeatability and reproducibility values for selected, representative components, and groups of components.
14.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and correct operation of the test method, exceed the repeatability values shown in Tables 9 and 10 only in one case in twenty.
14.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test materials would, in the long run, in the correct operation of the test method, exceed the values shown in Tables 9 and 10 only in one case in twenty.
NOTE 8 - Although the precision for benzene was determined in the range from 0.5 to 1.6 mass %, this test method can be used to determine benzene concentration up to 5.0 mass %.
14.2 Bias - No information can be presented on the bias of the procedure in Test Method D 6293 for measuring hydrocarbon types because no material having an accepted reference value is available.
15. Keywords
15.1 aromatics; gas chromatography; gasoline; hydrocarbon type; multidimensional gas chromatography; naphthenes; olefins; oxygenates; saturates; spark-ignition engine fuels
