Introduction: Daily consumption of liquid fuels for energy production purposes has led to release various contaminants into the atmosphere. Sulfur oxides and sulfate particulate matters are one important family of toxic compounds which are subjected to the health regulations. In the crude oil refining process, the presence of sulfur compounds leads to deactivation of catalyst materials and also cause pipeline corrosion. On the other hand, the presence of these compounds in fuel leads to the emission of sulfur oxide gasses to the atmosphere which further cause acid rain and also impacts human health [1, 2]. Therefore, desulfurization is a critical issue environmentally and economically which needs high attention. Methods/Experimental: Magnetic graphene oxide (MGO) has been used as both the catalyst for oxidation-extraction desulfurization (OEDS) and the adsorbent for magnetic solid-phase extraction/preconcentration of the oxidized sulfur compounds prior to ICP-OES measurements. Hydrogen peroxide and concentrated nitric acid were used as the oxidant and protonating agent, respectively. Different parameters which could affect desulfurization and extraction efficiencies were optimized using a multivariate experimental design. Results and Discussion: The results showed that under the optimized condition (the nanocatalyst amount, 20 mg; agitation time, 33 min; HNO3 and H2O2 volumes, 50 and 500 µL, respectively) removal efficiencies more than 97% were achievable using the proposed method. Also, sensitive determination of total sulfur concentration in kerosene, diesel and gasoline in the concentration range of 0.5 to 5.0 mg kg-1 with the detection and quantification limits of 0.15 and 0.5 mg kg-1 , respectively, under the optimized condition (optimized condition of desulfurization experiments and elution using 200 µL of methanol for 6.6 min) using the proposed method in combination with inductively coupled plasma optical emission spectrometry was achievable. The outstanding
