Characterization of organosulfur compounds in asphalt cement samples by ESI(+)FT-ICR MS and ¹³C NMR spectroscopy

Resumo

Herein, it is presented a methodology for the characterization of organosulfur compounds in asphalt cement (AC) samples employing solid-phase extraction (SPE) associated with methylation reactions and positive-ion mode electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI(+)FT-ICR MS) and carbon-13 nuclear magnetic resonance (¹³C NMR) spectroscopy. Three AC samples were submitted to an SPE separation, and the fractions obtained the original AC samples, and their maltenes were methylated and analyzed using the ESI(+)FT-ICR MS. The ESI(+)FT-ICR MS ionized the sulfur fractions much better than the original samples, detecting organosulfur compounds with a broader average molecular mass distribution (Mw). Several types of sulfur compounds were detected, such as sulfides, disulfides, thiophenes, and dibenzothiophenes. Besides, the ESI(+)FT-ICR data were compared with the ¹³C NMR (from model molecules analyses) and ESI(+)-Orbitrap MS. The organosulfur chemical profile was correlated to the physical properties of AC samples. It was verified that the samples with higher aromatic-character were less susceptible to aging test, while the one with more saturated-character presented more significant variation in their physical properties after the aging test.

Descrição

Palavras-chave

Organosulfur compounds, Asphalt cement, ESI(+)FT-ICR MS, Solid-phase extraction, ¹³C NMR, Asphalt aging

Citação

PORTO, Christiane F. C. et al. Characterization of organosulfur compounds in asphalt cement samples by ESI(+)FT-ICR MS and ¹³C NMR spectroscopy. Fuel, Amsterdam, v. 256, e115923, 2019. DOI: 10.1016/j.fuel.2019.115923. Disponível em: https://www.sciencedirect.com/science/article/pii/S001623611931275X?via%3Dihub. Acesso em: 21 jun. 2023.