A microvolume Curie-point pyrolysis short-column (5 m) gas chromatography/mass spectrometry (Py-GC/MS) procedure was developed for the characterization of various lipid moieties in microorganisms. High linear flow rates (approximately 175 cm/s) characterized the GC conditions in order to effect an efficient chromatographic transfer and elution of the underivatized diglycerides and monoglycerides, and small modifications were necessary to the ion trap MS system in order for it to accommodate the relatively high gas load. During a typical analysis run anhydrodiacylglycerides eluted within a 5-6-min time frame. Gram-positive bacilli and Gram-negative species were differentiated from each other by the pyrolysis patterns of their lipid components. In spite of the complexity of the analyte, a straightforward visual analysis was achieved with the aid of simple computerized data display procedures. These procedures included examination of (1) total ion current (TIC) profiles of the lipid region of the reconstructed chromatogram, (2) the integrated mass spectrum of this region, (3) selected reconstructed ion chromatograms (RICs), (4) RIC intensity distributions, and (5) corresponding mass spectra. An appealing aspect of the lipid data reduction procedure is that most of it can be accomplished visually without requiring computerized pattern recognition techniques.

Pyrolysis mass-spectra from a sample of the Al -horizon of a soH from southem Spain showed predominant peaks related to furan derivatives similar to those observed from complex polysaccharides in which not only hexoses but aiso pentoses and deoxyhexoses were constituent units. SmaHer peaks. typical for protein materials and phenolic units, were also observed. On the other hand. typical peaks for the methoxyphenols oí lignins were very small and indicated only limited amounts oC undecomposed lignín residues in this soH sample. Peaks related to benzene or toIuene were also very small.Humic acid samples from this soil showed much more prominent signals related to protein materíals, benzene and phenolic derivatives and weaker polysaccharide-related signals than did the entire sample. Typicallignin related peaks were smaIl or insignificant. Spectra from the grey or brown humidic acid fractions were much like those of the parent humic acid. Brown humic acid, however, showed stronger signals for nitrogen and sulphur compounds, indicating a higher content of protein-like materials in this fraction. Preparations of humic acid hydroIyzed by 6 N HCI showed in their pyrolysis products a marked increase in phenols and methoxyphenols.In its pyrogram, humin resembled humic acid, but signals for complex polysaccharides were more evident. Lignin-like materials seem not to be higher in this fraction. Hymatomelanic acid showed prominent signals related to polysaccharides and lignin. Pyrograms from the soH polysaccharides showed the characteristic pattern of a complex polysaccharide with the presence of fragments from polymers of amino acids or amino sugars. Fulvic acid spectra showed obvious dissimilarities to those from humic acid in that signals for protein, as well as those related to phenols, were low. Depending upon the isolation method, the fulvic acid preparations showed differing signals related to polysaccharide or phenolic materials.

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To demonstrate the potential of modern pyrolysis/mass spectrometry (Py-MS) for rapid characterization of oil shale kerogens and alginites of different geological and depositional origin, four key world oil shale kerogens and three alginites were analyzed by Curie-point Py-MS in combination with multivariate analysis methods such as factor and discriminant analysis. The pyrolysis mass spectra of the algal coal torbanite and the two recent alginites coorongite and botryococcus rubber reveal similar structural characteristics as observed in previous pyrolysis gas chromatographic/mass spectrometric (GC/MS) studies, including signatures of specific aliphatic hydrocarbon moieties produced by Botryococcus braunii. Moreover, application of a new time-resolved Py-MS technique reveals the rather heterogeneous nature of the two recent alginites coorongite and botryococcus rubber which contain several types of oxygen functionalities and exhibit complex thermal decomposition reactions, as opposed to the much more homogeneous nature of torbanite which shows a rather simple thermal decomposition behavior. The thermal decomposition patterns of the four kerogens derived from Green River, kukersite, tasmanite, and messel oil shales show an overall resemblance with torbanite. Factor and discriminant analysis of the pyrolysis mass spectra, however, reveal the existence of relatively minor but highly characteristic differences. For instance, the messel shale kerogen shows a significant hydroxyaromatic component, presumably reflecting contributions of terrestrial plant materials to the depositional environment. In contrast, the high sulfur signals of the tasmanite shale kerogen reveal a strong marine influence. The relationship between the Py-MS patterns in the discriminant analysis plot shows an overall resemblance with the relative positions of the kerogens in a Van Krevelen diagram. Consequently, it appears feasible to classify oil shale kerogens into the proper Tissot types (I–IV) on the basis of direct Py-MS results. It is concluded that computerized Py-MS techniques offer a highly promising approach to rapid structural characterization and classification of a potentially broad range of oil shale kerogens and alginites.