Laser-Induced Acoustic Desorption/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Petroleum Distillate Analysis

Abstract

Laser-induced acoustic desorption (LIAD) coupled with a 3-T Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR) allows the simultaneous analysis of both the nonpolar and polar components in petroleum distillates. The LIAD/FT-ICR method was validated by examining model compounds representative of the various classes of polar and nonpolar hydrocarbons commonly found in petroleum. LIAD successfully desorbs all the compounds as intact neutral molecules into the FT-ICR. Electron ionization (EI) at low energies (10 eV) and chemical ionization using cyclopentadienyl cobalt radical cation (CpCo*+) were employed to ionize the desorbed molecules. The EI experiments lead to extensive fragmentation of many of the hydrocarbon compounds studied. However, the CpCo*+ ion ionizes all the hydrocarbon compounds by producing only pseudomolecular ions without other fragmentation, with the exception of one compound (*CH3 loss occurs). Examination of two different petroleum distillate samples revealed hundreds of compounds. The most abundant components have an even molecular weight; i.e., they are likely to contain no (or possibly an even number of) nitrogen atoms.

Petroleomics: Chemistry of the underworld

“…§ Negative ion data were collected with similar parameters and appropriate polarity changes. Petroleum ions were typically singly charged, based on the unit m/z separation between 12 Cn and 13 C1 12 Cn-1 isotopic variants of the same elemental composition (59). FT-ICR mass spectra were internally calibrated with respect to a homologous series of ions present in high abundance in each sample.…”

“…We have, to date, resolved and identified Ͼ60,000 distinct elemental monoisotopic elemental compositions, 12 C c 1 H h 14 N n 16 O o 32 S s , from ions in positive-and negativeion ESI and APPI FT-ICR mass spectra of dozens of petroleum crude oil samples. [Species with one or more 13 C, 15 N, 34 S, etc.…”

“…efficient (and uniformly efficient) ionization of saturated hydrocarbons over a wide molecular mass range (12,13).…”

Experimental Investigations of the Internal Energy of Molecules Evaporated via Laser-Induced Acoustic Desorption into a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

“…LIAD has been successfully applied to the mass spectrometric analysis of a wide variety of analytes, including peptides, 10,15 dinucleoside phosphates, 16 saturated hydrocarbon polymers 17,18 and petroleum distillates. 19 An overall experimental characterization of the LIAD technique has been performed. 10,14, 20 However, a more detailed examination of the energies of LIAD evaporated molecules is needed.…”

Development of Spray Deposition/MALDI-TOFMS and Its Application to the Rapid Screening of Hydrolysis Products Derived from Nitrogen Mustards

“…Detailed procedures can be found in MALDI manuals, but operator skills and experience are also often important factors. It should be noted that some other interesting and potentially useful methods for sample introduction have been reported, which include, atmospheric pressure MALDI, 18,19 desorption/ionization on silicon nanowires, 20 laser-induced acoustic desorption, 21 ESI-MALDI, 22 electrospray sample deposition (ESD), 23 the use of carbon nanotubes 24 and AnchorChip TM sample preparation. 25 In this study, we wish to report on a new method for sample preparation, the spray deposition method, for use in conjunction with MALDI-TOFMS.…”