IP 531: Determination of sulfur content of automotive fuels - Low-background proportional counter energy-dispersive X-ray fluorescence spectrometry method

Overview:

Scope

This Standard specifies an energy-dispersive X-ray fluorescence (EDXRF) method for the determination of the sulfur content of automotive fuels having sulfur contents in the range from 7 mg/kg to 50 mg/kg.

For reasons of spectral overlap this Standard is not applicable to leaded gasolines, lead replacement gasolines containing 8 mg/kg to 20 mg/kg potassium, or to products and feedstocks containing lead alkyls, silicon, phosphorus, calcium, potassium, and halides if present at concentrations greater than one tenth of the measured concentration of sulfur, or more than 10 mg/kg, whichever is the greater. The most likely interference is chlorine that has been found in biodiesel derived from recycled vegetable oil. The presence of oxygenates or water may alter the sensitivity for sulfur.

NOTE - Operation of analysers using X-ray tubes is to be conducted in accordance with the manufacturer's safety instructions and federal, state and local regulations governing the use of ionising radiation.