Researchers have unveiled one of the fastest and most sensitive methods to date for detecting toxic per- and poly-fluoroalkyl substances (PFAS) that accumulate in the environment. These substances are associated with a range of health risks, including cancers and birth defects.
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PFAS have earned the name "forever chemicals" for a good reason — these man-made compounds, notorious for their persistence and slow degradation, can take thousands of years to break down.
They are pervasive and found in various everyday items, such as grease-resistant food packaging and water-repellent clothing. Alarmingly, PFAS have infiltrated nearly half of the US tap water supply.
Chemists from the New Jersey Institute of Technology have introduced a novel laboratory-based technique capable of detecting traces of PFAS from food packaging material, water, and soil samples in 3 minutes or less. The study was published in Elsevier’s Journal of Hazardous Materials.
Researchers suggest that their methodology could notably accelerate endeavors to investigate and mitigate the bioaccumulation of PFAS in the environment. This includes the utilization of over $2 billion in EPA grant funding allocated through President Biden's Bipartisan Infrastructure Law, aimed at enabling states to conduct water quality testing and treatment for these emerging contaminants.
There are thousands of different species of PFAS, but we’ve yet to understand the extent of their distribution in our environment because the current testing methods are costly and time-consuming, taking hours for sample preparation and analysis in some cases. What our study demonstrates is a much faster, sensitive, and versatile method that can monitor our drinking water, land, and consumer products for contamination in minutes.
Hao Chen, Study Corresponding Author and Professor, Chemistry, New Jersey Institute of Technology
Chen and his team assert that the novel method, which employs an ionization technique known as paper spray mass spectrometry (PS-MS) to analyze the molecular composition of sample materials, surpasses the current standard technique for PFAS testing, liquid chromatography/mass spectrometry, in terms of sensitivity. They report that their approach is 10-100 times more sensitive than the existing method.
PFAS can be ionized and rapidly detected by a high-resolution mass spectrometer, which gives a clear view of each PFAS species present and the degree of contamination down to a parts-per-trillion (ppt) level. For more complex matrices like soil, we’ve applied a related method called desalting paper spray mass spectrometry (DPS-MS) that washes away salts which normally suppress the ion signal of PFAS. Together, they greatly improve our ability to detect these compounds.
Hao Chen, Study Corresponding Author and Professor, Chemistry, New Jersey Institute of Technology
“Our limit of detection for PFAS is roughly 1ppt. For context, this amount has been likened to a drop of water in 20 Olympic-sized swimming pools,” states Md Tanim-Al Hassan, the paper’s first author and Ph.D. chemistry student at NJIT.
In their experiments, the team successfully detected PFAS in one minute or less by directly analyzing fragments of various food packaging materials, including microwave popcorn paper, instant noodle boxes, as well as fry and burger packaging from two multinational fast-food restaurant chains.
Their analysis unveiled traces of 11 different PFAS molecules, including common types such as PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctanesulfonic acid), which have been associated with elevated cancer risk and suppression of the immune system.
In their water analysis, the team detected traces of PFOA in samples of local tap water in under two minutes while finding no traces of PFAS in samples taken from the university’s filtered fountain water.
The EPA has already proposed to establish maximum contamination levels (MCLs) for six PFAS in drinking water nationwide, and PFOA and PFOS are among them. This analytical method could facilitate more intensive screenings for toxic PFAS that may be needed under such a proposal to protect the safety of our water supply.
Mengyan Li, Study Co-Author and Associate Professor, Environmental Sciences, New Jersey Institute of Technology
Utilizing DPS-MS, the team further identified two species of PFAS from as little as 40mg of soil in under three minutes.
Moreover, the team's swift detection method is currently undergoing testing to complement state-of-the-art techniques for remediating PFAS, which are being developed at NJIT's BioSMART Center.
“Remarkably, in our lab we were able to couple this analytical method to a novel degradation catalyst, which degrades 98.7% of PFAS in drinking water samples within three hours,” notes Wunmi Sadik, Study Co-Author and Chair of NJIT’s Department of Chemistry and Environmental Sciences.
Wunmi Sadik adds, “This work may have a national impact, but the immediate effect will be felt in the Northeast area. Roughly 10% of 9.2 million New Jersians have high levels of perfluorooctanoic acid in their drinking water compared to the national average of 1.9%.”
Chen highlights that this advancement could rapidly influence the monitoring of consumer products, spanning from cosmetics and medications to both fresh and processed foods. Additionally, the team intends to showcase the method's capabilities for air monitoring.
Chen concludes, “Near term, this could be extremely useful for ensuring the safety of food products … it may allow farming produce to be more efficiently monitored for PFAS contamination for example. Our method may also advance the study of airborne PFAS in a similar way to what we’ve demonstrated in this study, which would further help us address this widespread environmental issue.”
Journal Reference:
Hassan, Md. T.-A., et al. (2024). Rapid detection of per- and polyfluoroalkyl substances (PFAS) using paper spray-based mass spectrometry. Journal of Hazardous Materials. doi.org/10.1016/j.jhazmat.2023.133366.