As the dangers and long-term effects of PFAS come more into focus, detection for the so-called “forever chemicals” remains paramount, but also costly. It’s a hurdle researchers at the University of Massachusetts Amherst is looking to clear.
Nestled in the Life Sciences Laboratory building on the campus of UMass Amherst, sits a small apparatus – about the size of a desktop computer setup – complete with monitors and hardware for collecting data.
Beside it is a small chamber – and in it, a potential path toward a cheaper, more accessible way of detecting PFAS.
The invention, involving tech that costs around or under $40,000, is capable of detecting per- and polyfluoroalkyl substances or PFAS at levels as low as 400 parts per trillion.
It’s not quite the 4 parts per trillion the EPA called for in its latest drinking water safety standards addressing PFAS – but to develop a method for detecting it on the scale Liu and other researchers have, with hardware far, far cheaper than the industry standard, is a significant milestone.
“The instrument associated with mass spectrometry technology usually ranges from a few $100,000 to a million [dollars] to sometimes even $2 million … and also, it's a big, heavy instrument - needs highly-trained personnel and needs to be well-maintained from time to time,” says Dr. Chang Liu, an associate professor of the Department of Biomedical Engineering.
Some of the best current technology for testing for PFAS involves what’s known as liquid chromatography and mass spectrometry – done on expensive equipment that can be hampered by the residue of PFAS itself and isn’t readily accessible to many research labs.
Liu, Dr. Xiaojun Wei, a UMass Amherst research assistant professor, and other researchers are hopeful that could change in the near-future with a new testing method that’s been under development – potentially paving the way for a portable testing device to be developed.
It’s the subject of a new paper published in Science Advances – one featuring Wei as first author and Liu as a corresponding author.
In it, researchers establish how nanopore technology – already commercialized for things like DNA sequencing – can be used with a variant of the chemical molecule “cyclodextrin” to profile various types of PFAS.
The molecule itself has been the subject of studies for its potential PFAS removal abilities.
“Sometimes, we have a nanopore fabricated and then we use cyclodextrin as our model molecule to see if the pore is working or not,” Liu explains. “And then, we thought, ‘why don't we try … cyclodextrin?’ and immediately, we find something interesting.’”
The interesting result – a PFAS detection system.
“If we have cyclodextrin, it's going to show a first level signal, like, usually a rectangular shaped signal, and if we have PFAS in their tool, it's going to show second level signal on top of that first level signal that is very distinctive,” he says.
That second signal shape, Liu says, can also distinguish between different kinds of PFAS molecules.
The research also comes months after the EPA announced new drinking water standards designed to protect millions of Americans. Earlier this year, the agency declared that PFOA and PFOS, two of the most common PFAS pollutants, will be limited to 4 parts per trillion.
Other compounds including what are known as “GenX Chemicals” were given limits at 10 parts per trillion.
With more and more research confirming links between the forever chemicals and cancers, organ damage and developmental problems in children, effective detection systems are all the more invaluable.
As its researchers emphasize, though – the new testing method is still in its early stages. But as Liu tells WAMC, the path to better detection and possibly portable PFAS detectors is looking bright.
“Our study showed that we can reliably detect at 400 ppt level, but the goal is four, right?” says Liu. “So, there’s 100x difference, which is - I don’t think it’s very hard to achieve, because think about this: this is not like other biological or clinical samples that we usually work with that’s very delicate – [samples] you cannot heat… you cannot put it through a harsh environment, or harsh pH value. This is [a] forever chemical.”
