Mass Spectrometry coal extracts

Cagniant, D., Gmber, R., Lacordaire-Wilhelm, C, Schulten, H.-R. (1992) Pyrolysis-field ionization mass spectrometry of extracts separated from a gas coal and its macerals using N-methyl-2-pyrrohdinone. Energy Fuels, 6,702-708. 

High resolution mass spectrometry (qv) has been used with extracts of a series of coals to indicate the association of different heteroatoms (27). Various types of chromatography (qv) have also been used to identify the smaller species that can be extracted from coal. 

Seven Argonne Premium coal samples ranging from lignite to low volatile bituminous in rank were analyzed by Pyrolysis-Field Ionization Mass Spectrometry (Py-FIMS) in order to determine the existence and structural nature of a thermally extractable "mobile phase". In addition, Curie-point Pyrolysis-Low Voltage Mass Spectrometry (Py-LVMS) was employed to demonstrate the importance of mild oxidation on the thermally extractable mobile phase components. 

Temperature-programmed vacuum pyrolysis in combination with time-resolved soft ionization mass spectrometry allows principally to distinguish between two devolatilization steps of coal which are related to the mobile and non-mobile phase, respectively. The mass spectrometric detection of almost exclusively molecular ions of the thermally extracted or degraded coal products enables one to study the change of molecular weight distribution as a function of devolatilization temperature. Moreover, major coal components can be identified which are released at distinct temperature intervals. 

White et al. (65) positively identified a variety of thiophenes in a Bevier seam coal extract. Using low-voltage high-resolution mass spectrometry they were able to observe low concentrations of compounds in the extract that had molecular formulae consistent with those of some thiols, sulfides and disulfides. It should be emphasized however, that no thiol, sulfide or disulfide was positively identified in the extract. 

Comparison of Hydrocarbons Extracted from Seven Coals by Capillary Gas Chromatography and Gas Chromatography-Mass Spectrometry... 

Several groups of hydrocarbon biological markers were identified in the coal extracts by mass spectrometry using selected ion scans. n-Alkanes, pristane, sesquiterpenes, several tricyclic alkanes and pentacyclic triterpanes with molecular weights from 398 to 454 were detected. 

The application of and N.M.R. spectroscopy, gas chromatography (G.C.) and mass spectrometry (M.S.) in the separation and identification of alkanes extracted from fossil fuels is illustrated with three Turkish lignites (including one extracted by supercritical gas), coal tar and petroleum crude. Elution of hydrocarbons from a silica-gel column may be monitored by N.M.R. and molecular-sieve sub-fractionation into normals and branched/cyclics by G.C., together with... 

Over the last two decades, developments in G.C., mass spectrometry (M.S.), N.M.R. spectroscopy and other physical techniques have appreciably extended the ability of chemists to undertake detailed analyses of fractions extracted from coal and other fossil fuels. In this paper, we survey some of the characterization techniques for alkanes, emphasising particularly... 

The hydrocarbon ("oil") fraction of a coal pyrolysis tar prepared by open column liquid chromatography (LC) was separated into 16 subfractions by a second LC procedure. Low voltage mass spectrometry (MS), infrared spectroscopy (IR), and proton (PMR) as well as carbon-13 nuclear magnetic resonance spectrometry (CMR) were performed on the first 13 subfractions. Computerized multivariate analysis procedures such as factor analysis followed by canonical correlation techniques were used to extract the overlapping information from the analytical data. Subsequent evaluation of the integrated analytical data revealed chemical information which could not have been obtained readily from the individual spectroscopic techniques. The approach described is generally applicable to multisource analytical data on pyrolysis oils and other complex mixtures. 

John, P., Johnson, C.A.F., Parker, J.E., Smith, G.P., Herod, A.A., Gaines, A.F., Li, C.-Z., Kandiyoti, R. (1991) High mass material (>10 daltons) in a coal liquefaction extract, by laser desorption mass spectrometry. Rapid Commun. 

Domin, M., Moreea, R., Lazaro, M.-J., Herod, A.A., Kandiyoti, R. (1997) Choice of extraction voltage and matrix in the MALDI-TOF mass spectrometry of coal tar pitch-pyridine insolubles. Rapid Commun. Mass Spectrom., 11, 638-645. 

Figure 13 Time-resolved Curie-point pyrolysis MS total ion signal profile of a coal sample obtained at a heating rate of 100 K s- (A) and the deconvolution of the second maximum (at SIO C) into at least three components (b-d) by means of factor analysis (B). Tentative interpretation of components a-d was based on comparison of numerically extracted spectra with the actual spectra of maceral concentrates. Numbers in parentheses show the percent of the total variance for each component. Reproduced by permission of Plenum Press from Meuzelaar HLC, Yun Y, Chakravarty T and Metcalf GS (1992) Computer-enhanced pyrolysis mass spectrometry a new window on coal structure and reactivity. In Meuzelaar HLC (ed) Advances in Coal Spectroscopy. New York Plenum Press.

Wang, J., Tomlinson, M.J., and Caruso, J. A. (1995). Extraction of trace elements in coal fly ash and subsequent speciation by high-performance liquid chromatography with inductively coupled plasma mass spectrometry.J. A a/./4(. Spectrom. 10(9), 601. 

---