The use of forensic polycyclic aromatic hydrocarbon signatures and Compound Ratio Analysis Techniques (CORAT) for the source characterisation of petrogenic/pyrogenic environmental releases.

This study utilised recent developments in forensic aromatic hydrocarbon fingerprint analysis to characterise and identify specific biogenic, pyrogenic and petrogenic contamination. The fingerprinting and data interpretation techniques discussed include the recognition of: The distribution patterns of hydrocarbons (alkylated naphthalene, phenanthrene, dibenzothiophene, fluorene, chrysene and phenol isomers), • Analysis of “source-specific marker” compounds (individual saturated hydrocarbons, including n-alkanes (n-C5 through 0-C40) • Selected benzene, toluene, ethylbenzene and xylene isomers (BTEX), • The recalcitrant isoprenoids; pristane and phytane and • The determination of diagnostic ratios of specific petroleum / non-petroleum constituents, and the application of various statistical and numerical analysis tools. An unknown sample from the Irish Environmental Protection Agency (EPA) for origin characterisation was subjected to analysis by gas chromatography utilising both flame ionisation and mass spectral detection techniques in comparison to known reference materials. The percentage of the individual Polycyclic Aromatic Hydrocarbons (PAIIs) and biomarker concentrations in the unknown sample were normalised to the sum of the analytes and the results were compared with the corresponding results with a range of reference materials. In addition, to the determination of conventional diagnostic PAH and biomarker ratios, a number of “source-specific markers” isomeric PAHs within the same alkylation levels were determined, and their relative abundance ratios were computed in order to definitively identify and differentiate the various sources. Statistical logarithmic star plots were generated from both sets of data to give a pictorial representation of the comparison between the unknown sample and reference products. The study successfully characterised the unknown sample as being contaminated with a “coal tar” and clearly demonstrates the future role of compound ratio analysis (CORAT) in the identification of possible source contaminants.

Development of sensing systems for environmental monitoring

This project focused on the investigation and the development of a chemical sensing system for the determination of chromium Cr6+ and a bio-reactor followed by electrochemical detection at a glassy carbon electrode, for the determination of organochlorine compounds. The conjugation of Cr6+ with 1,5-diphenylcarbazide was studied at various types of electrodes such as glassy carbon, ultra-trace epoxy-graphite, chemically or un-modified carbon-paste and dropping-mercury. The cyclic voltammetric behaviour of the complex was also investigated. In addition, the possibility of developing a chemical sensor, Le. an electrochemical probe capable of sensing Cr6+ through its complexation with 1,5-diphenylacarbazide was studied. The conjugations of l-chloro-2,4-dinitrobenzene, 2,4-dichloronitrobenzene and ethacrynic, which are electrophilic organochlorine compounds, with reduced glutathione, were studied in order to test the bioreactor developed, based on the immobilisation of glutathione s-transferase. This was carried out at different types of electrodes such as glassy-carbon, gold, silver, platinum, epoxy-graphite, hangingmercury, and ferrocene-modified rotating-disc electrodes.

Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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Oeuvres complètes de Buffon, augmentées par M.F. Cuvier de deux volumes supplémentaires, offrant la description des mammifères et des oiseaux les plus remarquables découverts jusqu'à ce jour ...

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