EXPLANATION
The quality of gasoline is related to the amount of sulfur present. Knowledge of sulfur content is necessary for processing purposes. Regulations by federal, state, and local agencies restrict the amount of sulfur present in gasoline as it affects performance characteristics and potential corrosion problems and emission levels. Certain jurisdictions may restrict the amount of sulfur in gasoline to prevent or limit environmental pollution caused by sulfur oxide emissions formed from sulfur in the fuel during combustion of fuel.
This is a rapid and precise method for measurement of sulfur in petroleum products with a minimum of sample preparation. This method covers the sulfur measurement in the range 49 to 1000 mg/kg in nonleaded gasoline and gasoline-oxygenate blends.
TEST SUMMARY
The sample is placed in a beam emitted from an X-ray source. The resultant excited characteristic X radiation is measured, and the accumulated count is compared with counts from previously prepared calibration standards to obtain the sulfur concentration.
Compounds such as oxygenates present in the sample can affect the apparent sulfur readings. Such matrix effects can be compensated by many modern instruments.
TEST PRECISION
Where X is the sulfur concentration in mg/kg.
Bias is not known.