Carbon-13 NMR spectra of macerals separated from individual coals

An Essay on the Organic Geochemistry of Coal

“…Nevertheless, it was clear that there was a wide spread of structural characteristics, such as the presence of carbonyl groups, olefinic double bonds, and aromatic rings, among the various samples. Such chemical work as has been performed on sporinite macérais, using a variety of techniques, shows that they are at least partly aromatic (/ a = 0.4-0.5), and contain abundant straight-chain (or lightly branched) aliphatic structures Larter, 1981, 1983;Winans et al, 1981;Pugmire et al, 1981aPugmire et al, 1982Wilson et al, 1984). and Shaw (1970) apparently believe that sporo pollenin is preserved intact in the sporinite macérais of both Cretaceous and Carboniferous coals.…”

“…Some work has been done on concentrates of other macérais, prepared either from British and Australian lithotypes by float-and-sink methods or by the density gradient procedure of Dyrkacz et al (1981a) from United States coals (Retcofsky and VanderHart, 1978;Zilm et al, 1981;Pugmire et al, 1981bPugmire et al, , 1982Pugmire et al, , 1983aMaciel et ai, 1982;Wilson et al, 1984). Some work has been done on concentrates of other macérais, prepared either from British and Australian lithotypes by float-and-sink methods or by the density gradient procedure of Dyrkacz et al (1981a) from United States coals (Retcofsky and VanderHart, 1978;Zilm et al, 1981;Pugmire et al, 1981bPugmire et al, , 1982Pugmire et al, , 1983aMaciel et ai, 1982;Wilson et al, 1984).…”

Environmental NMR – the early years

“…, these already produced new information on the overall C composition of soil organic matter, but the CPMAS combination was quickly applied to any type of sample that could be pushed into a rotor. Some early applications included fossil fuels, and intense interest in the different forms of cellulose, including crystalline, and more amorphous (or surface) forms . Note that the first two were published simultaneously in the Journal of the American Chemical Society, one immediately following the other.…”

Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Final technical report, Volume 1 - effects of solvents, catalysts and temperature conditions on conversion and structural changes of low-rank coals

“…Thus CP/MAS 13C NMR has become a standard technique to measure aromaticity. There is a tremendous amount of work reported in the recent literature using this technique to study coal and other geochemical samples [Hatcher et al, 1981[Hatcher et al, , 1982a[Hatcher et al, &b, 1983Wilson et al, 1981Wilson et al, , 1983aWilson et al, , 1984Zilm et al 1981;Lambert and Fxye, 1982;Preston and Ripmeester, 1982;Pugmire et al, 1982;Benzing-Purdie and Ripmeester, 1983;Skjemstad et al 1983;Steelink et al, 1983;Thurman and Malcolm, 1983;Pfeffer et al 19841. Regarding the accuracy of aromaticity, caution should be taken when interpreting fa's of materials containing considerable quantities of paramagnetic materials.…”