Direct Analysis of Oil Additives by High-Field Asymmetric Waveform Ion Mobility Spectrometry-Mass Spectrometry Combined with Electrospray Ionization and Desorption Electrospray Ionization

Abstract

The analysis of corrosion inhibitors in the presence and absence of an oil matrix is reported using electrospray ionization (ESI) and desorption electrospray ionization (DESI), hyphenated with miniaturized high-field asymmetric waveform ion mobility spectrometry (FAIMS) and mass spectrometry (MS). The target analytes were successfully ionized in solution by ESI and directly from steel surfaces using DESI ambient ionization at levels ≥0.0004% w/w (4 ppm) in oil. Differences in the mass spectral profiles observed for the additive/oil mixture are attributed to differences between the ESI and DESI ionization processes. The use of FAIMS improved selectivity for ESI generated analyte ions through reduction in the chemical noise resulting from the oil matrix. DESI enabled the direct, rapid, native state interrogation of oil samples on steel surfaces without sample pretreatment, and the hyphenation of DESI with the miniaturized FAIMS enhanced the relative analyte responses of the surface-active corrosion inhibitors.

Ambient Ionization and FAIMS Mass Spectrometry for Enhanced Imaging of Multiply Charged Molecular Ions in Biological Tissues

“…Several groups have explored the use of FAIMS, as well as other ion mobility techniques, for MSI applications. 24–28 A lab-built DMS cell integrated with a DESI platform was used to image glycerophosphocholines (PC) in a mouse brain tissue, resulting in decreased chemical noise, as well as improved S/N and image contrast. 29 More recently, liquid extraction surface analysis (LESA) was integrated with the FAIMS device we applied in our study to image proteins in mouse brain and liver tissue samples.…”

Atmospheric pressure matrix‐assisted laser desorption/ionization mass spectrometry of engine oil additive components

“…The composition of these tribofilms has been extensively investigated by various measurement techniques, such as X-ray photoelectron spectroscopy (XPS), 8,[10][11][12][13] X-ray absorption spectroscopy, [14][15][16] and transmission electron microscopy (TEM) combined with focused ion beam (FIB) cutting. 17 Other available techniques include X-ray absorption near edge structure (XANES), 16,18 RAMAN spectroscopy, 19 scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), 8,[20][21][22] Fourier-transform infrared (FTIR) spectroscopy, 23,24 electrospray ionization mass spectrometry (ESI-MS), 25,26 high-field asymmetric waveform ion mobility spectrometry coupled with mass spectrometry (FAIMS-MS), 27 or dynamic time-of-flight secondary ion mass spectrometry (TOF-SIMS). 28 Direct surface analysis techniques such as desorption electrospray ionization (DESI-MS) 29 oil analysis and direct analysis in real time coupled with mass spectrometry (DART-MS) 30 have been applied for quantitative analysis of a commercial lubricant antioxidant additive in a base oil, while mass spectrometric imaging (MSI) by means of laser desorption/ionization reflectron time-of-flight mass spectrometry (LDI-RTOF-MS) was used to analyse ex situ oil components applied as lubricant additives in a tribological layer of a tribologically stressed surface.…”

Comparison of Thermal and Flow-Based Modulation in Comprehensive Two-Dimensional Gas Chromatography—Time-of-Flight Mass Spectrometry (GC × GC-TOFMS) for the Analysis of Base Oils

“…Chemical additives and antioxidants are typically added to an oil or lubricant to enhance its performance, alleviate adverse properties, and prevent oxidation [8,9]. Antioxidants are added to eliminate or slow down the oxidation processes to which hydrocarbons are prone at high temperatures [9].…”