Separation of polycyclic aromatic sulfur heterocycles among themselves and also from interferents in petrochemical matrices is a challenging task because of their low concentration, matrix complexity, and also due to the presence of polyaromatic hydrocarbons, as they present similar physico-chemical properties. Therefore, the objective of this work was preparation, characterization, and application of a stationary phase for separation of these compounds in a heavy gas oil sample and their identification by comprehensive two-dimensional gas chromatography. The stationary phase was prepared by grafting mercaptopropyltrimethoxisilane onto a silica surface, followed by palladium(II) chloride immobilization. Elemental analysis, thermogravimetry, nitrogen adsorption-desorption isotherms, infrared analysis, and scanning electron microscopy were performed to characterize this solid phase. Sulfur compounds were separated in an open column packed with the stationary phase and analyzed by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection. The number of compounds tentatively identified was 314 and their classes were thiophenes, benzotiophenes, dibenzothiophenes, naphthothiophenes, benzonaphthothiophenes, and dinaphthothiophenes. Separation among sulfur compounds and polyaromatic hydrocarbons was successful, which is a difficult goal to achieve with the traditionally employed solid phases. Some recalcitrant compounds (dibenzothiophenes with substituents of two and four carbons) were fully separated and tentatively identified.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.