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

• Published in: Journal of Chromatography A Vol. 1470; pp. 104 - 110
• Main Authors: Bjerk, Thiago R., de Menezes, Eliana W., Pereira, Marcelo B., Caramão, Elina B., Benvenutti, Edilson V., Zini, Cláudia A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 28-10-2016
• Subjects: Chemical Fractionation; Comprehensive two-dimensional gas chromatography; Fuel Oils - analysis; Gas Chromatography-Mass Spectrometry; GC × GC; Heavy gas oil; Ligand exchange chromatography; Organic sulfur compounds; Palladium - chemistry; Silica Gel - chemistry; Silver - chemistry; Silver ion silica gel; Sulfhydryl Compounds - chemistry; Thiophenes - isolation & purification; Ligand exchange chromatography; Organic sulfur compounds; Comprehensive two-dimensional gas chromatography; GC×GC; Silver ion silica gel; Heavy gas oil
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2016.09.064

•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.