New PFAS detection methods to help reduce contaminants

In a bid to help clean up per- and polyfluoroalkyl substance (PFAS) contamination, Curtin University researchers have developed a method to accurately detect and measure levels of the pollutant, one which is easier to administer and produces real-time readings.

PFAS are potentially harmful chemical materials that were used in various commercial and industrial settings, which are infamous for their toxicity and persistence within the environment once released.

In collaboration with Universidad Nacional de Córdoba, the research was published in the journal Analyst.

Curtin University School of Molecular and Life Sciences Professor Damien Arrigan said removal of the materials from the environment is one of the only ways of ensuring they do not enter the food chain.

“As a result of their widespread use, many groundwater and soil sites around the world are contaminated with these materials, which are often referred to as ‘forever chemicals’, because they don’t breakdown or degrade in the natural environment,” Arrigan said.

“The only way to prevent them entering the food chain, is to minimise or remove the chemicals from the environment — making early detection a highly desirable part of this removal process.”

Up until now, testing has required taking soil or water samples from a site in order to undertake chemical analysis in a laboratory, a process that can take several days.

On-site sensors

Researchers worked to improve the testing process by using on-site chemical sensors, which allow an instant contamination test that indicates the samples that require more detailed laboratory analysis.

“The chemical sensors we developed use electrodes to push ionised PFAS across an oil-water interface, or ‘boundary,’ using special glass membranes with microholes,” Arrigan said.

“This process changes the electrical properties of the interface and gives us an electrical current that tells us about the concentration of substances.”

Argrigan said the method also allows for a more sensitive reading of the contaminants presence in samples, one which accurately indicates whether or not the levels are safe or not.

“This method allows us to not only detect the presence of perfluorooctane sulfonate, one of the most widely used PFAS, but also measure it at very low concentration levels — lower than the concentration values set for safe limits of this substance in drinking water,” he said.

“Our preliminary results show that with our new method, it is possible to immediately detect very small concentrations of PFAS substances in waters, without the need to send the samples offsite for initial analysis.

“With appropriate development into a more portable, robust technology, this method could potentially be used by industry and government agencies, and the general public, to monitor PFAS concentration in water and soils and get results within minutes, rather than days.”