ASTM D6730 Standard Test Method for Determination of Individual Components in Spark Ignition Engine Fuels by 100-Metre Capillary (with Precolumn) High-Resolution Gas Chromatography
14. Sample Analysis Procedure
14.1 Adjust the instrument operating variables to the values specified in Table 1 or as determined in Section 12.
14.2 Set the recorder or integration device, or both, for accurate presentation and collection of the data.
14.3 Inject an appropriate size sample (as determined in Section 10) into the injection port and start the analysis. Obtain a chromatogram and a peak integration report.
15. Calculation
15.1 Identify each peak by matching retention indices (or retention times) with those for known reference standards or sample components. If a computing integrator is used, examine the chromatographic data for proper peak integration. Examine the report to ensure peaks are properly identified.
15.1.1 Proper component identification using retention indices requires the use of windows surrounding each RI value in order to account for the analysis to analysis variations. The following windows have been found to provide satisfactory identification for this test method.
15.2 Obtain the area for each peak. Multiply each peak area by its appropriate response factor, taken from Table 2 or determined separately with standards, to obtain corrected peak areas. Use a response factor of 1.000 for unknown peaks.
15.3 If required, determine the concentration of water in the sample using Test Method D1744, or an equivalent method. The total concentration of any other materials not determined by this test method should also be obtained.
15.4 The corrected peak areas are normalized to 100 % or to 100 % minus the concentrations determined in 15.3.
component % (m/m) = corrected peak area x (100 - % undetected)/total corrected peak area