Abstract: The total sulfur content in light oils was determined by ultraviolet fluorescence (UVF) spectrometry and the influence factors of impurities of oxygen, nitrogen, chlorine and metallic elements on the analysis accuracy were investigated by different types of instruments. Results show that oxygen has no influence on the accuracy of determination of sulfur content, indicating that the UVF method is especially suitable for determination of sulfur content of methanol gasoline, ethanol gasoline, biodiesel and biodiesel blends, and also suitable to the light oils with chlorine content less than 100μg/g. It is found that nitrogen has great influence on the accuracy of sulfur determination, and the interference extent relates to the instruments made by different factories. When the nitrogen in samples is more than 100μg/g, the influence of nitrogen must be taken into account. It is also found that no obvious effect is observed in the determination of sulfur content when the content of lead, manganese and iron is no more than 26 mg/L or silicon is less than 100mg/L.

Key words: ultraviolet fluorescence, light oil, sulfur, determination method