EXPLANATION
See Explanation in the Test Method ASTM D6730 on the previous page.
TEST SUMMARY
A representative sample of the petroleum liquid is introduced into a gas chromatograph equipped with an open tubular (capillary) 100 meter column coated with a methyl silicone liquid phase modified with a capillary precolumn. Helium carrier gas transports the vaporized sample through the column, in which it is partitioned into individual components which are sensed with a flame ionization detector as they elute from the end of the column. The detector signal is presented on a strip chart recorder or digitally, or both, by way of an integrator or integrating computer. Each eluting component is identified by comparing its retention time to that established by analyzing reference standards or samples under identical conditions. The concentration of each component in mass % is determined by normalization of the peak areas after correction with detector response factors. Unknown components are reported as a total unknown mass %.
TEST PRECISION
