SULFUR DETERMINATION IN GASOLINE BY WD-XRF: ASTM D6334
EXPLANATION
This test method is applicable to gasoline and gasoline-oxygenate blends in the sulfur concentration range of 15 to 940 mg/kg. Similar to other XRF methods just described, the standards and samples must match in their matrix composition.
TEST SUMMARY
The sample is placed in the X-ray beam, and the intensity of the sulfur K line at 5.373 Å is measured. The intensity of the corrected background, measured at the wavelength of 5.190 Å is subtracted from this intensity. The resultant net counting rate is then compared to a previously prepared calibration curve or equation to obtain the concentration of sulfur in mg/kg.
TEST PRECISION
In the 15 to 940 mg/kg range, this test method has a repeatability and a reproducibility 0.0400(X + 97.29) and 0.1182(X + 54.69), respectively, where X is the mean sulfur concentration in mg/kg.
There was no bias in the results between this test method and other Test Methods ASTM D2622, ASTM D3210, ASTM D4045, ASTM D4294, and ASTM D5453.
