EXPLANATION
Frequently the knowledge of individual sulfur compounds present in a product is more useful than the total amount of sulfur present. This test method covers the determination of volatile sulfur compounds in light petroleum liquids. This test method is applicable to distillates, gasoline motor fuels, including those containing oxygenates, and other petroleum liquids with the FBP of approximately 230°C or lower at atmospheric pressure. Generally, this test method can determine individual sulfur species at levels of 0.1 to 100 mg/kg. This test method does not purport to identify all individual sulfur compounds present. Also, some sulfur compounds, such as hydrogen sulfide and mercaptans, are reactive and their concentration in samples may change during sampling and analysis. Total sulfur content of the sample can be estimated from the sum of the individual compounds determined. However, this test method is not the preferred method for the determination of total sulfur in a petroleum liquid.
TEST SUMMARY
The sample is analyzed by gas chromatography with an appropriate sulfur selective detector. Calibration is done by an appropriate internal or external standard. All sulfur compounds are assumed to produce equivalent response as sulfur. As sulfur compounds elute from the gas chromatographic column, they are quantified by a sulfur selective chemiluminescence detector that produces a linear and equimolar response to sulfur compounds.
TEST PRECISION
Bias of this test method has not been determined.