Comparison of Atmospheric Pressure Ionization for the Analysis of Heavy Petroleum Fractions with Ion Mobility-Mass Spectrometry

Abstract

Because of its high molecular complexity, ultra high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is used to characterize heavy petroleum distillates. However, high peak capacity can also be obtained with ion mobility-mass spectrometry (IM-MS). In this case, the additional separation dimension allows for the compensation of the lower resolving power of the time-of-flight mass analyzer. The processing and elemental composition assignments from such bidimensional IM-MS data cannot be achieved with conventional software packages. PetroOrg, a new software package, was used to compare IM-MS data sets recorded with atmospheric solid analysis probe (ASAP) and three other atmospheric pressure ionization sources. The choice of the ionization source is indeed very critical as it defines the type of compounds that can be detected from mixtures. Electrospray ionization (ESI) is very specific to polar compounds and yields relatively simple data sets that can be readily attributed to nitrogen containing compounds allowing their speciation. On the other hand, gas phase ionization methods such as APCI, APPI, and ASAP yielded valuable information concerning thiophenic species. However, in this case the IM-MS peak capacity is not sufficient to separate all isobaric species. It is worth noting that ASAP and APPI yielded similar mass spectra although the ASAP ionization mechanism is believed to be closer to that of APCI. Most likely this is due to the absence of solvent with ASAP that reinforces charge exchange processes and therefore affords low ionization discrimination such as with APPI.

Estimating the intermediate precision in petroleum analysis by (±)electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

“…The complexity of crude oil 8,9 associated with the use of high‐resolution FT‐ICR MS makes the interpretation of petroleomics data a laborious step. In general, the processing of mass spectra is accomplished by software packages (Composer, 10 PetroOrg, 11 etc.) that can allow the recognition of isotopic profiles and the assignment of molecular formulae (C c H h N n O o S s ) from the m / z signals.…”

Paraffin-Inert Atmospheric Solid Analysis Probe: A Fast and Easy Approach To Characterize Extremely Air-Sensitive Organometallic Complexes by Mass Spectrometry

“…36 The ASAP source has been used in many applications for both targeted analysis [37][38][39] and untargeted analysis. [40][41][42] Unlike other techniques that require uncontrolled multi sophisticated preparation steps or modified setups, 43,44 in our new simple approach, referred to as paraffin-inert ASAP (piASAP), 45 a capillary tube containing air-sensitive compounds (liquid or solid) is sealed with paraffin plug under inert atmosphere condition. The sample is thus protected in a sealed glass capillary under inert atmosphere.…”

Molecular Fingerprints and Speciation of Crude Oils and Heavy Fractions Revealed by Molecular and Elemental Mass Spectrometry: Keystone between Petroleomics, Metallopetroleomics, and Petrointeractomics

“…More compounds were ionized by APPI than by the other ionization sources, and ESI was the most selective source. Similarly, Farenc et al 28 compared the direct introduction of heavy petroleum fractions using ESI, APCI, APPI and atmospheric solid analysis probe (ASAP). The ASAP source was shown to provide a similar ionization profile as APPI, as it is capable of speciating sulfur-containing species.…”