Identification and Quantitation of Linear Alkanes in Lubricant Base Oils by Using GC×GC/EI TOF Mass Spectrometry

Contributions of Molecular Dynamics Simulations to Elastohydrodynamic Lubrication

“…This is despite the recent observation that experimental data for a large number of molecular systems at high pressure may be described by a common repulsive potential U(r) ∝ r −12 [60]. Thus, one area certainly worthy of further study is the identification of the most suitable potential to represent the non-bonded interactions for MD simulations of lubricant-sized hydrocarbons (C 10 -C 40 [76]) at high pressures. This could perhaps be facilitated by re-parameterizing MD force fields using first principles calculations with accurate representations of van der Waals interactions [77].…”

“…The mixture viscosities were successfully predicted using the Grunberg-Nissan mixing rules [82] over the entire pressure range. Despite significant recent progress, MD simulations of the high-pressure viscosity of lubricant-sized molecules (C 10 -C 40 [76]) are still a computationally demanding and time-consuming task. An interesting recent development by Kajita et al [83] has been to dramatically accelerate (by three orders of magnitude) the evaluation of viscosity using a femtosecond stress-tensor correlation.…”

Comprehensive Screening of Polycyclic Aromatic Hydrocarbons and Similar Compounds Using GC–APLI–TIMS–TOFMS/GC–EI–MS

“…PAHs are traditionally analyzed by gas or liquid chromatography coupled to mass spectrometry (GC–MS or LC–MS , ). However, the natural complexity of PAH-containing samples makes their selective detection difficult, especially when monodimensional separations are combined with in-source fragmentation techniques such as EI . Two-dimensional gas chromatography coupled to mass spectrometry (GC×GC–MS) − emerged as a natural evolution of GC–MS to increase the peak capacity and the number of identifications, gaining popularity for oil characterization in recent times.…”

“…However, the natural complexity of PAH-containing samples makes their selective detection difficult, especially when monodimensional separations are combined with insource fragmentation techniques such as EI. 8 Two-dimensional gas chromatography coupled to mass spectrometry (GC×GC− MS) 9−11 emerged as a natural evolution of GC−MS to increase the peak capacity and the number of identifications, 9 gaining popularity for oil characterization in recent times. However, the latter technique suffers from drawbacks such as high costs of consumables and a complex operation, 12 requiring highly specialized personnel and high operating budgets.…”

Quantitative Analysis of Hydrocarbons in Gas Oils by Two-Dimensional Comprehensive Gas Chromatography with Vacuum Ultraviolet Detection

“…13−19 In these works, electronic ionization is the most commonly used ionization mode, and a soft ionization source has also been employed in some cases. 20 In this field, the work of Jennerwein et al 13 has shown that proper automated identification may be obtained from GC × GC-MS thanks to adequate Visual Basic scripts that take into account specific m/z fragments for a given family. Making this method quantitative required a complex method to determine MS response factors based on the analysis of numerous standards.…”