Document Type

Book Chapter

Publication Date


Journal / Book Title

Vitrinite Reflectance as a Maturity Parameter: Applications and Limitations


Chemical analyses restricted to a single coal maceral permit a focus on rank effects without concern for variations in organic matter type. Vitrinite concentrates of high purity were isolated from coal samples of the Lower Kittanning seam by multi-step density gradient centrifugation, with reflectances ranging from 0.66 to 1.39% Rmax. In addition to the previously recognized losses of phenolic compounds, the vitrinite pyrolyzates exhibit marked increases in relative concentrations of tri- and tetraaromatic hydrocarbons (especially benzo[a]fluorene, methyl-phenanthrenes, methylfluorenes and methylchrysenes) above 0.9% Rmax, i.e., beyond the "second coalification jump" of Teichmüller. Thus, petrographically-recognizable physical transformations are shown to correspond to a major chemical restructuring of the vitrinite. Increases in rank also correspond to systematic variations in the distributions of the isomers of various polyaromatic compounds in the flash pyrolyzates, which can be exploited in the creation of indicators covering a wide range of thermal maturation.



Book Publisher

ACS Publicarions

Journal ISSN / Book ISBN


Book Editor(s)

Mukhophadyay, P. K. and Dow, W.G.

Published Citation

Kruge, M.A. and Bensley, D.F., 1994, Flash pyrolysis-gas chromatography/ mass spectrometry of Lower Kittanning vitrinites: Changes in the distributions of polyaromatic hydrocarbons as a function of coal rank. In, Mukhophadyay, P. K. and Dow, W.G., eds., Vitrinite Reflectance as a Maturity Parameter: Applications and Limitations. American Chemical Society Symposium Series 570, p. 136-148.