Mass-spectra of dimethylbicyclo64.4.09decane stereoisomers (2,3-; 2,4-; 2,8- and 2,9-dimethylbicyclo64.4.09decanes)

Brodskii, Ye.S.; Lukashenko, I. M.; Musayev, I.A.; Kurashova, E.Kh.; Sanin, P.I.

doi:10.1016/0031-6458(77)90056-9

Cited by 2 publications

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“…Examination of the C 12 bicyclane mass spectra and comparison with the plotted mass spectra of the tabulated values reported by Brodskii et al led to the tentative identification of two dimethylbicyclo[4.4.0]decane isomers (Figure S-12 in the Supporting Information). Furthermore, two major peaks and four later eluting minor peaks had NIST mass spectral matches with 1- and 2-ethylbicyclo[4.4.0]decane isomers (Figure S-13A–F in the Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Structural Identification of Petroleum Acids by Conversion to Hydrocarbons and Multidimensional Gas Chromatography-Mass Spectrometry

Wilde

Rowland

2015

Anal. Chem.

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Identification of individual petroleum acids ("naphthenic" acids, NA) has proved challenging for decades, due to the extreme complexity of many petroleum acid mixtures. This has hindered detailed understanding of the role of NA in petroleum generation and oil production processes, refinery corrosion, as wood preservatives, and as environmental toxicants. Some recent advances have been made due to improved chromatographic separation of esters of the acids by multidimensional gas chromatography-mass spectrometry (GC × GC-MS), but relatively few reference spectra of esters are available for comparison. Here we report a complementary method based on a combination of a modified historical approach of converting NA to the corresponding hydrocarbons, followed by analysis by GC × GC-MS. Many published spectra exist for reference hydrocarbons making comparisons of reference spectra with those of the unknowns, much more feasible. As an example, we report identification of over 30 individual bicyclic naphthenic acids as the bicyclane hydrocarbons. These include both fused and bridged acids possessing methyl, dimethyl, and ethyl alkyl substituents as well as some terpenoid-derived acids. The study provides the most comprehensive analysis of one of the major classes of NA (the bicyclic acids) to date. There is now clear potential for this method to be used for the structural elucidation of other unknown acids (e.g., oil sands acids) and functionalized biomarkers in complex mixtures.

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Section: Resultsmentioning

confidence: 99%

Structural Identification of Petroleum Acids by Conversion to Hydrocarbons and Multidimensional Gas Chromatography-Mass Spectrometry

Wilde

Rowland

2015

Anal. Chem.

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Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography–mass spectrometry

Wilde

West

Scarlett

et al. 2015

Journal of Chromatography A

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Although bicyclic acids have been reported to be the major naphthenic acids in oil sands process-affected water (OSPW) and a well-accepted screening assay indicated that some bicyclics were the most acutely toxic acids tested, none have yet been identified. Here we show by comprehensive multidimensional gas chromatography-mass spectrometry (GC×GC-MS), that >100 C8-15 bicyclic acids are typically present in OSPW. Synthesis or purchase allowed us to establish the GC×GC retention times of methyl esters of numerous of these and the mass spectra and published spectra of some additional types, allowed us to identify bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[4.3.0]nonane, bicyclo[3.3.1]nonane and bicyclo[4.4.0]decane acids in OSPW and a bicyclo[2.2.2]octane acid in a commercial acid mixture. The retention positions of authentic bicyclo[3.3.0]octane and bicyclo[4.2.0]octane carboxylic acid methyl esters and published retention indices, showed these were also possibilities, as were bicyclo[3.1.1]heptane acids. Bicyclo[5.3.0]decane and cyclopentylcyclopentane carboxylic acids were ruled out in the samples analysed, on the basis that the corresponding alkanes eluted well after bicyclo[4.4.0]decane (latest eluting acids). Bicyclo[4.2.1]nonane, bicyclo[3.2.2]nonane, bicyclo[3.3.2]decane, bicyclo[4.2.2]decane and spiro[4.5]decane carboxylic acids could not be ruled out or in, as no authentic compounds or literature data were available. Mass spectra of the methyl esters of the higher bicyclic C12-15 acids suggested that many were simply analogues of the acids identified above, with longer alkanoate chains and/or alkyl substituents. Our hypothesis is that these acids represent the biotransformation products of the initially somewhat more bio-resistant bicyclanes of petroleum. Although remediation studies suggest that many bicyclic acids can be relatively quickly removed from suitably treated OSPW, examination by GC×GC-MS may show which isomers are affected most. Knowledge of the structures will allow the toxicity of any residual isomers to be calculated and measured.

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Mass-spectra of dimethylbicyclo64.4.09decane stereoisomers (2,3-; 2,4-; 2,8- and 2,9-dimethylbicyclo64.4.09decanes)

Cited by 2 publications

References 0 publications

Structural Identification of Petroleum Acids by Conversion to Hydrocarbons and Multidimensional Gas Chromatography-Mass Spectrometry

Structural Identification of Petroleum Acids by Conversion to Hydrocarbons and Multidimensional Gas Chromatography-Mass Spectrometry

Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography–mass spectrometry

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