Abstract
Saudi Arabian crude oil is a super complex mixture and, up to now, there has been little research into its heteroatom-containing compounds. First, oxygenated compounds (OCs) were isolated from Saudi Arabian oil using a Pd nanoparticle exchange complex, which formed between the nano-Pds and the oxygenated ligands. Normally, polycyclic aromatic sulphur heterocycles (S-PAHs) are separated from petroleum oil via the same method. The obtained results reveal that all the OC formulations with S-PAHs can be separated from the pre-isolated aromatic fraction of crude oil via this approach. S-PAHs are mixtures of benzothiophene and dibenzothiophene congeners. The isolated OCs are composed mainly of hydroxyl compounds. The liquid chromatography (LC)/electrospray ionization (ESI) in positive ion mode ESI(+)/tandem mass spectrometry (MS/MS) technique was used to assign the molecular weight distribution and identify the isolated OCs. The LC/ESI (+)-MS/MS technique differentiates S-PAHs and OCs using protonated ions. Thus, LC/ESI(+)-MS/MS can be used to assign molecular weight distributions for both the groups as a single mixture. MS/MS in precursor ion mode was used for the immediate identification of the target S or O analytes.