Silver bonded to silica gel applied to the separation of polycyclic aromatic sulfur heterocycles in heavy gas oil

- Ag-MPSG material was characterized and used in LEC to separate PASH of HGO.
- Ag-MPSG is a promising phase to replace Pd-MPSG due to its performance and lower cost.
- Fractionation of HGO with Ag-MPSG followed by GC × GC/MS resulted in 168 OSC identified.
- The use of Ag-MPSG resulted in the identification of some OSC not yet reported in HGO.

Silica gel containing silver ions was prepared and characterized. Silica was organofunctionalized with 3-mercaptopropyl group by using grafting reaction followed by silver ions adsorption (silver covalently bonded to mercaptopropyl silca gel, Ag-MPSG). The organofunctionalization and silver coordination were observed by transmission infrared spectroscopy and elemental analyses (CHN and EDS). The textural characteristics were studied by N2 adsorption-desorption isotherms. Additionally, optical properties were studied by diffuse reflectance spectroscopy. The Ag-MPSG material was employed as stationary phase for the first time for fractionation of a heavy gas oil sample resulting in a fraction that is richer in polycyclic aromatic sulfur heterocycles (PASH). The fractions were analyzed by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detector and Ag-MPSG material provided similar fractionation performance when compared to conventional material [palladium covalently bonded to mercaptopropyl silca gel, Pd(II)-MPSG] usually employed for the same purpose and as the cost of silver is less than the one of palladium, the cost of the fractionation phase was reduced.