Phytotoxicity of branched cyclohexanes found in the volatile fraction of diesel fuel on germination of selected grass species

MacKinnon, G. and Duncan, H.J. (2013) Phytotoxicity of branched cyclohexanes found in the volatile fraction of diesel fuel on germination of selected grass species. Chemosphere, 90(3), pp. 952-957. (doi: 10.1016/j.chemosphere.2012.06.038)

Abstract

During a larger study to screen candidate plant species for phytoremediation of diesel fuel-contaminated soils, it was observed that at relatively low levels of diesel fuel contamination, delayed shoot/root emergence and reduced germination was observed for the majority of plant species investigated. It was theorised that these effects were the result of acute phytotoxicity, caused by the volatile fraction of diesel fuel, with results supporting this theory. This finding was investigated further in the current study. Headspace analysis of diesel fuel showed that between 5% and 10% of diesel fuel consisted of compounds that would volatilise at 20 °C, with the most predominant compounds identified being the isomers of xylene (m-, o- and p-), n-alkanes (C9–C12) and alkylbenzenes. There were also low levels of toluene, branched cyclohexanes (methyl-, to butylcyclohexane) and alkenes. Of particular interest were branched cyclohexanes as little work has previously been reported on these compounds. To explain the phytotoxic effect of the volatile fraction of diesel fuel and attribute the effect to a specific compound or group of compounds within diesel fuel, seeds were germinated in petri dishes contaminated with a number of pure branched cyclohexanes. An unusual pattern of germination was apparent, with results varying depending on grass species and the length of cyclohexane branching. Results showed ethyl- and butyl-cyclohexane had a significant effect on the germination rate of selected grass species whereas methyl- and propyl-cyclohexane had little effect.

• Item Type: Articles
• Additional Information: NOTICE: this is the author’s version of a work that was accepted for publication in Chemosphere. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Chemosphere (2012) DOI: 10.1016/j.chemosphere.2012.06.038
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: MacKinnon, Dr Gillian
• Authors: MacKinnon, G., and Duncan, H.J.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Chemosphere
• Publisher: Elsevier Ltd
• ISSN: 0045-6535
• Published Online: 21 July 2012
• Copyright Holders: Copyright © 2012 Elsevier
• First Published: First published in Chemosphere 90(3):952-957
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher