Structure Elucidation and Sulfur Species Characterization of Asphaltenes Derived from Heavy Fuel Oil Using APPI (+) and ESI (+) FT-ICR Mass Spectrometry. - Al-Khelaiwi, Muhannad S.; Siddiquee, Muhammad N.; Campuzano, Felipe; Saxena, Saumitra; Roberts, William L.; Abdul Jameel, Abdul Gani (Arabian Journal for Science & Engineering (Springer Science & Business Media B.V. ), 2025)