Researchers have found a novel approach to identify per- and polyfluoroalkyl substances (PFAS) in water. This development represents a significant advancement in the creation of testing devices that are easier to use, more affordable, quicker, and generally more accessible than currently available methods.
University of Massachusetts Amherst researchers have found a novel approach to identify per- and polyfluoroalkyl substances (PFAS) in water. This development represents a significant advancement in creating testing devices that are easier to use, more affordable, quicker, and generally more accessible than currently available methods.
PFAS, often referred to as forever chemicals, are recognized as a major environmental pollutant.
These substances persist in nature due to their resistance to degradation and pose serious health risks. Being exposed to these chemicals has been linked to a range of cancers (such as kidney, testicular, breast, ovarian, prostate, thyroid, and childhood leukemia), as well as liver and heart damage and developmental issues in infants and children.
Earlier this year, the Environmental Protection Agency (EPA) introduced the first national safety standard for PFAS in drinking water at 4 parts per trillion (ppt). “PPT means parts per trillion. So in a trillion water molecules, only 4 are PFAS. We need to detect even these trace amounts,” explains Chang Liu, associate professor of biomedical engineering at UMass Amherst and the lead author of the study published in the journal Science Advances detailing their new detection method.
Currently, the most reliable way to test for PFAS involves liquid chromatography paired with mass spectrometry. However, this technique necessitates expensive equipment costing millions and involves complex extraction processes, making it non-portable. “Additionally, the long-lasting nature of PFAS residues can reduce the precision of these instruments over time,” states Xiaojun Wei, the primary author of the paper and research assistant professor at UMass Amherst.
Their research shows that a compact and low-cost device can successfully detect several PFAS families at concentrations as low as 400 ppt. Although this initial prototype does not match the sensitivity or the variety of PFAS types detectable by mass spectrometry, the researchers believe it has significant potential.
“We are reducing the cost of the instrument from millions to a few thousand dollars,” says Liu. “We need improved technology to detect PFAS that is more accessible, affordable, and user-friendly, with more on-site testing. That is our goal.”
The researchers also envision using this method as a preliminary screening tool to pinpoint which water sources present the highest health risks.
Their testing device operates by adding a molecule known as cyclodextrin to a compact device commonly used for DNA sequencing, called a nanopore. The well-established “host-guest” interaction between cyclodextrin and PFAS has been documented, but Liu notes that no one had previously used it in combination with a nanopore for detection. “We are now utilizing a molecule called HP-gamma-Cyclodextrin as an adaptor in an alpha-Hemolysin nanopore,” he explains, effectively creating a PFAS detector.
Liu hopes their findings will raise awareness about the dangers posed by PFAS and ultimately result in the commercialization of a portable PFAS detector for monitoring water quality in the field.
