Abstract <p>The need to obtain lighter hydrocarbon products from organic compounds, including bitumen extracted from oil sands in contact with the atmosphere, requires the study of chemical transformations in their composition<i>.</i>This chemical transformation is characterized by a change in the composition of bitumen and its oxidation under the influence of sunlight. In this work, changes in the structure of aromatic hydrocarbons of oxidized organic compounds in oil sand samples from the Girgishlag-Girdagh outcrop of Eastern Azerbaijan under the influence of sunlight were studied using ultraviolet (UV), infrared (IR) and luminescent methods. Two hours of photoirradiation resulted in the formation of cyclic peroxides, endoperoxides and hydroxynones from polycyclic aromatic hydrocarbons (PAHs). Cyclic peroxides, formed under the influence of high-energy photons, disappeared when exposed to polychromatic rays. Thus, our experimental studies allow us to evaluate the mechanism of the oxidation process and its time-dependent existence in bitumen oxidized under the influence of sunlight. This approach can be considered as one of the criteria for assessing the possibilities of obtaining fuel and energy products from oil sands and heavy hydrocarbons.</p>