Liquid chromatography/field ionization mass spectrometry in the analysis of high-boiling and nondistillable coal liquids for hydrocarbons

Applications of Noncontact Atomic Force Microscopy in Petroleum Characterization: Opportunities and Challenges

“…To overcome the limitation on volatile molecules, liquid fractionation methods according to solubility or adsorption properties were developed, such as the saturates, aromatics, resins, and asphaltenes (SARA) analysis. − Since the 1980s, many liquid chromatographic techniques have been broadly applied to the nondistillable fractions. For example, the separation of vacuum residuum into acids, bases, and neutrals fractions by McKay and Boduszynski using ion-exchange chromatography led to the significant insights into the continuous distribution of petroleum compositions. − However, identification of individual compounds in heavy petroleum remained a great challenge even for liquid chromatography.…”

Molecular Characterization of Heavy Petroleum by Mass Spectrometry and Related Techniques

“…58−61 Figure 3 illustrates examples of APPI, PESI, and NESI mass spectra (a mass segment with m/z between 740.4 and 741.8) of a vacuum residue. 40 APPI yielded mostly molecular ions (oddelectron configuration) of hydrocarbon compounds (HC) and their 13 C isotopes (top). PESI yielded protonated molecule ions (even-electron configuration) containing one nitrogen (1N) and their isotopes (middle), and NESI yielded deprotonated species (even-electron configuration) containing two oxygen (2O) and one nitrogen (1N) compounds (bottom).…”

“…Detailed characterization of petroleum molecules boiling below 1000 °F has been established in the last century based on gas chromatography (GC), , mass spectrometry (MS), ,− and preparative-liquid chromatographic (LC) separations. ,− The characterization of petroleums boiling above 1000 °F, such as VR, is much more challenging because of their high boiling point and high molecular weights. In addition, these heavy petroleum fractions typically contain significant amounts of asphaltenes (i.e., n -heptane or n -pentane insolubles) due to their rich heteroatom contents (S, N, O, and metals) and low H/C ratios.…”

Simplified Hydrocarbon Compound Type Analysis Using a Dynamic Batch Inlet System Coupled to a Mass Spectrometer

“…The first hydrocarbon type analysis methods were developed to operate in the electron ionization (EI) mode under high-energy [2][3][4][5][6][7] (50-70 eV) or low-energy [8][9][10][11][12][13][14] (∼10 eV) ionization regimes. More recently other ionization methods such as chemical ionization, [15][16][17] field ionization/ desorption, [18][19][20][21] and thermospray ionization, 22 have been introduced for hydrocarbon type analysis. The various ionization techniques can either transfer considerable amounts of internal energy upon ionization, and hence lead to the generation of fragment ions, [2][3][4][5][6][7] or transfer sufficient internal energy to form the molecular ion but insufficient energy to generate fragment ions [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] (soft ionization).…”

“…More recently other ionization methods such as chemical ionization, [15][16][17] field ionization/ desorption, [18][19][20][21] and thermospray ionization, 22 have been introduced for hydrocarbon type analysis. The various ionization techniques can either transfer considerable amounts of internal energy upon ionization, and hence lead to the generation of fragment ions, [2][3][4][5][6][7] or transfer sufficient internal energy to form the molecular ion but insufficient energy to generate fragment ions [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] (soft ionization). The generation of mass spectra consisting primarily of molecular ion species greatly simplifies the analysis due to the absence of fragment ions and provides direct information on the molecular weight distribution of the sample.…”