This International Standard specifies a method for the determination of the sulfur content by oxidative microcoulometry of petroleum light and middle distillates with a final boiling point not higher than 400 °C. It is applicable to materials with sulfur contents in the range of 1 mg/kg to 100 mg/kg. Products with sulfur contents above 100 mg/kg can be analysed after dilution with a suitable sulfur-free solvent. Products with sulfur contents below 1 mg/kg can also be analysed by a modified technique described in Annex A. The precision quoted only applies to measurements in the 1 mg/kg to 100 mg/kg range. Nitrogen interferes with the analysis at concentrations above 0,1 % (m/m), and chlorine interferes at concentrations above 1,0 % (m/m), but these interferences are overcome by the addition of sodium azide to the cell electrolyte. Bromine and organometallic compounds also interfere with the analysis at concentrations above approximately 500 mg/kg.