Potter - Analytical and environmental chemistry

Our molecular sensing research is associated with the development and application of polymer technology and advanced instrumental methods of analysis. We prepare Polymer Inclusion Membranes (PIMs) and polymer-based microspheres for use as small-scale chemical reactors and sensors for biological, environmental and industrial applications.

We develop methods to analyse plant biomarkers in collaboration with colleagues from the Department of Economic Development, Jobs, Transport and Resources (DEDJTR), Victoria. We have identified and detected chemical biomarkers that indicate early levels of stress in grape vines resulting from grape phylloxera infestation. We have also quantified the induced changes in the amounts of indole glucosinolates in brassica plants after infection by plant bacterial pathogens. This work identified several bioactive compounds that could be used in screening and breeding programs aimed at producing brassica varieties with high human bioefficacy and improved plant disease resistance.

In collaboration with colleagues from the Victoria Police Forensic Services Department (VPFSD) and the Defence, Science & Technology Group (DSTG) we develop forensic analysis methods to determine the production method and source of dangerous chemicals.

Research areas

Remediation of environmental waters by arsenic removal using polymer inclusion membranes

Arsenic is a metalloid widely spread in the earth's crust and is often found in conjunction with copper, gold, lead and iron in metal sulphide ores. The depletion of arsenic from ore deposits can lead to the presence of arsenic in aquifers and water streams. In recent years, the number of people exposed to arsenic in drinking water has increased. Prolonged drinking of arsenic contaminated water can cause serious health issues, including cancers. This risk to public health has increased the necessity for alternate, easy-to-use and environmentally friendly techniques for arsenic removal.

Polymer inclusion membranes (PIMs) have recently emerged as a promising alternative to conventional liquid-liquid extraction for the extraction and removal of various organic and inorganic pollutants from aqueous solutions. PIMs consist of three main components: a polymer to provide mechanical support, a carrier as the extractant for the targeted analyte, and a plasticizer or modifier to influence the physiochemical properties of the PIM. Investigating the chemistry of extraction is important because the membrane composition can have a significant effect on the selectivity and extent of analyte extraction. Our aim is to investigate the chemistry of inorganic arsenic removal from water using newly developed carriers, and to optimise the PIM performance for arsenic speciation and transport.

Provenance determination of Ricinus communis by trace elemental analysis

The castor bean plant (Ricinus communis) is an introduced perennial shrub found throughout Australia that contains the toxin ricin within its seeds. Ricin, the toxin popularised by the TV series Breaking Bad, is listed as a Schedule 1 toxin by the Department of Foreign Affairs and Trade and a Category B (second highest in priority) bioterrorism agent by the US Centers for Disease Control and Prevention. This is due to the easy accessibility to the castor bean plant and simple purification of the toxin, which is fatal through multiple modes of contact at extremely low doses. Historically ricin has been implicated as the lethal agent for the assassination of Georgie Markov in 1979. The ability to classify unknown samples of R. communis by comparing the elemental profile to established region-specific trends would be beneficial to law enforcement and forensic agencies.

Following on from preliminary findings, R. communis specimens and their corresponding soil profiles will be collected from VIC, NSW, QLD, WA, SA, and central Australia as part of this research project. Detailed characterisation of the soil profiles from each sampling site across all capital cities, and all other population centres of significance, will be undertaken to establish the variability between these locations. Analysis of the elemental profile of these samples will assist in establishing the similarities and differences between the soil profile and the seeds and, importantly, the identification of trace elements responsible for the interstate and intrastate discrimination of R. communis.

Applications of membrane technology for the sensing and extraction of polyaromatic hydrocarbons (PAHs)

PAHs are considered some of the most carcinogenic and persistent pollutants. Membrane separation process technology has a variety of applications. There have been significant breakthroughs for conventional applications in water and wastewater purification, industrial gas separations (H2, N2, CO2, etc) and chlor-alkali electrolytic cells. However, the development of membranes for hydrocarbon processing, especially of olefins and aromatics, has not been as successful.

Our research focuses on the application of membrane technology, in particular the use of polymer inclusion membranes (PIMs), for the decontamination of PAHs, as troublesome model pollutants, from environmental and oil refinery waste waters. PAHs are particularly challenging to selectively extract because of their limited water solubility, and the lack of chemical functional groups to exploit through selective chemistry. The challenge is to develop a suitable membrane to extract and separate PAHs from water streams.

Picloram is the most persistent herbicide of the chlorobenzoic acid family in use today. Its decomposition is usually a slow and incomplete process. The removal of herbicide residues from environmental waters where the complete photo-degradation is not a viable option is quite essential. We are working to develop polymer inclusion membranes for the extraction, as well as the sensing, of picloram and its potential degradation products from environmental waters.

Meet the team

Group members

Potter GroupGroup leader

Dr Ian Potter

PhD students

Ahmed Al-Adhab
Zarah Alzahrani
Michael Chan
Mais Mohammed
Alinanuswe Mwakalesi

Masters student

Silvia Vesga-Martínez

Honours student

Emily Graham

Volunteer research associate

Leda Hidalgo

Publications

See a full list of publications on Google Scholar [external link], ResearchGate [external link], ResearcherID [external link] or view Dr Ian Potter's profile.