Reference : Compositional elucidation of heavy petroleum base oil by GC×GC-EI/PI/CI/FI-TOFMS
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Chemistry
Compositional elucidation of heavy petroleum base oil by GC×GC-EI/PI/CI/FI-TOFMS
Giri, Anupam [SABIC > Analytical GTC Europe > > >]
Coutriade, Marion [TOTAL > TOTAL marketing et service > > >]
Racaud, Amandine [TOTAL > TOTAL marketing et service > > >]
Stefanuto, Pierre-Hugues mailto [Université de Liège - ULiège > Département de chimie (sciences) > Chimie analytique, organique et biologique >]
Okuda, Koji [JEOL USA > > > >]
Dane, John [JEOL USA > > > >]
Cody, Robert [JEOL USA > > > >]
Focant, Jean-François mailto [Université de Liège - ULiège > Département de chimie (sciences) > Chimie analytique, organique et biologique >]
Journal of Mass Spectrometry
Yes (verified by ORBi)
United States
[en] Comprehensive two‐dimensional gas chromatography (GC×GC) coupled to time‐of‐flight mass spectrometry is a powerful separation tool for complex petroleum product analysis. However, the most commonly used electron ionization (EI) technique often makes the identification of the majority of hydrocarbons impossible due to the exhaustive fragmentation and lack of molecular ion preservation, prompting the need of soft‐ionization energies. In this study, three different soft‐ionization techniques including photo ionization (PI), chemical ionization (CI), and field ionization (FI) were compared against EI to elucidate their relative capabilities to reveal different base oil hydrocarbon classes. Compared to EI (70 eV), PI (10.8 eV) retained significant molecular ion (M+‧) information for a large number of isomeric species including branched‐alkanes and saturated mono‐cyclic hydrocarbons along with unique fragmentation patterns. However, for bi‐/poly cyclic naphthenic and aromatic compounds, EI played upper hand by retaining molecular as well as fragment ions to identify the species, whereas PI exhibited mainly molecular ion signals. On the other hand, CI revealed selectivity towards different base oil groups, particularly for steranes, sulfur‐containing thiophenes, and esters; yielding protonated molecular ions (M+H) + for unsaturated and hydride abstracted ions (M‐H+) for saturated hydrocarbons. FI, as expected, generated intact molecular ions (M+‧) irrespective to the base oil chemical classes. It allowed elemental composition by TOFMS with a mass resolving power up to 8,000 (FWHM) and a mass accuracy of 1 mDa, leading to the calculation of heteroatomic content, double bond equivalency, and carbon number of the compounds. The qualitative and quantitative results presented herein offer a unique perspective into the detailed comparison of different ionization techniques corresponding to several hydrocarbon classes.

File(s) associated to this reference

Fulltext file(s):

Restricted access
Giri_et_al-2018-Journal_of_Mass_Spectrometry.pdfPublisher postprint1.15 MBRequest copy

Bookmark and Share SFX Query

All documents in ORBi are protected by a user license.