Pyrolysis GC–MS and THM-GC–MS studies of a black coating from Little Lost River Cave, Idaho

Characterisation of organic inclusions in stalagmites using laser-ablation-micropyrolysis gas chromatography–mass spectrometry

“…• The DOM in the black Nullarbor Plain speleothem 370 FS03 differed from the other samples in the trends of the n-alkenes and shorter chain n-alkanes, and in the smaller range of aromatic and nitrogen compounds. This is consistent with the proposed dominance of humic acids as the cause for the colouration in these samples [22], in the light of some research on pyrolysis of humic acids [24]. However, the absence of some compounds may be a function of the low abundance of pyrolysable material in the sample, rather than in the nature of that material, meaning that a direct comparison with other OM types must be approached with caution.…”

“…Their dominance in a pyrogram has previously been associated with humic acids [24], although it has also been suggested that this dominance is a result of an inherent analytical bias in favour of non-polar compounds [33]. The results here indicate that interrogation of the relative chain length distribution within each group (n-alkenes; n-alkanes <C 20 ; n-alkanes >C 20 ) is informative in partially separating the three sample types.…”

“…Homologous series of n-alkenes and n-alkanes are frequently seen from the pyrolysis of organic matter [33,24,2], deriving from the pyrolysis breakdown of larger biopolymers. Their dominance in a pyrogram has previously been associated with humic acids [24], although it has also been suggested that this dominance is a result of an inherent analytical bias in favour of non-polar compounds [33].…”

Recent applications in analytical thermochemolysis

“…In another study, a black coating of an overlying rock painting in Little Lost River Cave No. 1 in Idaho was analyzed with both thermochemolysis-TMAH and analytical pyrolysis [124]. The presence of acetamide and propionamide (chemical markers from bacteria) and markers of humic materials were confirmed indicating that the coating is not related to painting materials.…”

Age of Black Coloured Laminae Within Speleothems from Domica Cave and Its Significance for Dating of Prehistoric Human Settlement

“…The lack of any other, except dying components, non-carbonate particles excludes the possibility of their transport from soil by percolating water. Moreover, the hydrophobic character of the components in question further denies the possibility of their transport by water from soil overlying the cave (see discussion in Fezzey and Armitage, 2006). Hence, the dying components originated inside the caves as a by-product of human activity.…”