Oxidative desulphurization received attention as an alternative or an additional technology for deep fuel desulphurization. We studied oxidative desulphurization as an approach to remove sulphur organic compounds in light cycle oil. By FTIR spectroscopy appropriate conditions for oxidation have been experimentally identified as up to 90% of the sulfur compounds in LCO were removed. This spectroscopic technique allowed sulphones quantification by 1302 cm(-1) band interpretation. Inasmuch sulphones have higher polarity than the parent sulphide molecules they are preferentially extracted from the feedstock. FTIR analysis permits to estimate degree of the sulphur compounds oxidation, degree of desulphurization by extraction method and to register micro quantity of oxidized products. (C) 2009 Elsevier B.V. All rights reserved.