Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry
© 2014 Elsevier B.V. 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 compr...
| Main Authors: | , , , , , , |
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| Format: | Journal Article |
| Published: |
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/46644 |
| _version_ | 1848757617038458880 |
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| author | Wilde, M. West, C. Scarlett, Alan Jones, D. Frank, R. Hewitt, L. Rowland, S. |
| author_facet | Wilde, M. West, C. Scarlett, Alan Jones, D. Frank, R. Hewitt, L. Rowland, S. |
| author_sort | Wilde, M. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © 2014 Elsevier B.V. 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. |
| first_indexed | 2025-11-14T09:30:56Z |
| format | Journal Article |
| id | curtin-20.500.11937-46644 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:30:56Z |
| publishDate | 2015 |
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| spelling | curtin-20.500.11937-466442017-09-13T14:08:02Z Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry Wilde, M. West, C. Scarlett, Alan Jones, D. Frank, R. Hewitt, L. Rowland, S. © 2014 Elsevier B.V. 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. 2015 Journal Article http://hdl.handle.net/20.500.11937/46644 10.1016/j.chroma.2014.12.008 restricted |
| spellingShingle | Wilde, M. West, C. Scarlett, Alan Jones, D. Frank, R. Hewitt, L. Rowland, S. Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title | Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title_full | Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title_fullStr | Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title_full_unstemmed | Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title_short | Bicyclic naphthenic acids in oil sands process water: Identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| title_sort | bicyclic naphthenic acids in oil sands process water: identification by comprehensive multidimensional gas chromatography-mass spectrometry |
| url | http://hdl.handle.net/20.500.11937/46644 |