Gas-Phase Reactions of ClMn(H₂O)⁺ with Polar and Nonpolar Hydrocarbons in a Mass Spectrometer

Abstract

The gas-phase reactions of ClMn(H2O)+ with a variety of volatile and nonvolatile, saturated and unsaturated hydrocarbons have been examined by using Fourier transform ion cyclotron resonance mass spectrometry (FT/ICR). The ClMn(H2O)+ ion reacts rapidly by exclusive H2O ligand displacement with all the hydrocarbons studied, including highly branched alkanes that usually fragment upon ionization. These observations are rationalized on the basis of the electronic structure of ClMn+. Collision-activated dissociation of the product ions provides structural information which promises to allow the distinction and structural characterization of isomeric hydrocarbons. These findings suggest that the ClMn(H2O)+ ion is a highly promising chemical ionization reagent for mass spectrometric characterization of hydrocarbons, including those that commonly exist in petroleum

HPLC/APCI Mass Spectrometry of Saturated and Unsaturated Hydrocarbons by Using Hydrocarbon Solvents as the APCI Reagent and HPLC Mobile Phase

“…Unfortunately, the mass spectrometric characterization of hydrocarbons and their mixtures, such as biofuels, is challenging due to the shortcomings of current ionization methods. For example, ESI [12], SSI [10,11], and matrix-assisted laser desorption/ionization [13] (MALDI) are limited to ionization via protonation, deprotonation, and cation attachment [14,15], which means that these methods cannot ionize analytes without easily ionizable functional groups, such as saturated hydrocarbons [16,18]. Ambient analysis of saturated hydrocarbons by using dischargeinduced oxidation in desorption electrospray ionization (DESI) has been reported [19].…”

“…Atmospheric pressure photoionization (APPI) can ionize nonpolar polycyclic aromatic hydrocarbons but it cannot be used to ionize saturated hydrocarbons [22]. Laserinduced acoustic desorption (LIAD)/Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR) using ClMn(H 2 O) + as the chemical ionization reagent ion has been reported to allow the evaporation and ionization of nonpolar hydrocarbons without fragmentation under ultrahigh vacuum, but this approach requires special instrumentation [16,17].…”

Investigation and Applications of In-Source Oxidation in Liquid Sampling-Atmospheric Pressure Afterglow Microplasma Ionization (LS-APAG) Source

“…In recent years, numerous plasma-based ionization techniques under atmospheric pressure or ambient conditions [13][14][15][16][17] are emerging as powerful tools for rapid analysis of diverse analytes, which can also employ Breactive^plasma as the ionization reagent to initiate various types of reactions [18][19][20][21], including conventional chemical reactions, electrochemical or photochemical reactions, and gas-phase ion-molecule reactions. In-source oxidation, as a common reaction in the ionization process, should be avoided in routine analysis but has been successfully applied in structural analysis [7].…”

Ambient analysis of saturated hydrocarbons using discharge-induced oxidation in desorption electrospray ionization

“…In spite of these difficulties, traditional hydrocarbon analysis in the petroleum industry continues to be an important subject. Recently, laser-induced acoustic desorption (LIAD) coupled with gas-phase ion/molecule reactions under vacuum has shown great potential to achieve efficient ionization of saturated hydrocarbons with little [1] or no [5] fragmentation. Direct analysis of hydrocarbons under ambient conditions remains highly desirable however, because it allows easy implementation on both commercial and portable mass spectrometers of on-site analysis and has the potential for high throughput screening.…”