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BUFFALO, N.Y. — The first-ever federal restrictions on per- and polyfluoroalkyl substances (PFAS) in drinking water were created last year. Municipalities throughout the country are working to upgrade their water systems to detect and remove PFAS, which take so long to break down they’ve earned the nickname “forever chemicals.”

But what about the PFAS in the breath you just took? 

There are currently no federal regulations for PFAS air emissions. In fact, the U.S. Environmental Protection Agency (EPA) is still in the process of developing a standardized method for capturing and measuring PFAS in air emissions.

Now, University at Buffalo researchers say they have created a novel, effective method for PFAS air emission detection that could help shape federal guidance. Described in a recent study published in , the method captures gaseous PFAS and enables their direct injection into an analytical instrument to precisely measure their concentration.

The method is specifically tailored to capture volatile PFAS, a class of PFAS that easily evaporate and travel through the air, allowing them to contaminate areas far away from their original source of emission. 

“Water is only one pathway through which PFAS enter the environment. A significant portion of PFAS can also exist in the gas phase. Ignoring air as a medium of analysis overlooks a critical part of the puzzle in understanding how these contaminants spread," says the study’s lead author, Emanuela Gionfriddo, PhD, associate professor of chemistry in the UB College of Arts and Sciences. “The more methods to measure PFAS we have in the analytical toolbox, the more comprehensively we can monitor these toxic compounds.”

PFAS are a group of manmade chemicals widely used in consumer products that have been linked to cancer, infertility and developmental delays. While some legacy PFAS have been phased out, such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), their precursors continue to be used.

These include volatile PFAS, such as fluorotelomer alcohols (FTOHs), which can convert to legacy PFAS under the right environmental conditions. 

Due to their tendency to quickly evaporate, volatile PFAS present a challenge for standard detection methods. The EPA has drafted a method for detecting volatile PFAS, known as Other Test Method 50, but it was designed for a much broader group of chemicals known as volatile fluorinated compounds (VFCs).

“Without an effective strategy to capture volatile PFAS, we risk losing them during sample preparation and consequently failing to detect them in the analytical process," Gionfriddo says.

To ensure enough molecules are captured, Gionfriddo’s team used an analytical chemistry technique known as headspace solid-phase microextraction (HS-SPME) to capture volatile PFAS and transfer them into a gas chromatography-mass spectrometry (GC-MS) instrument, in a single step. 

The process involves placing a miniature probe above volatile PFAS-spiked water within a sealed container. When the volatile PFAS evaporates and the molecules rise, the probe is there to capture them. 

The method ultimately was able to quantify volatile PFAS at parts-per-trillion concentrations.

“We analyzed the main conditions that affect the capture of the PFAS, such as the temperature of the water and length of exposure of the probe and then ran quality control samples to ensure our measurement of the PFAS was precise,” says the study’s co-first author, Madison Williams, a PhD candidate in Gionfriddo’s lab. 

Another advantage to their method is that it’s more sustainable. By capturing the molecules and injecting them into the quantitative instrument in a single step, the process does not require the organic solvents typically needed to push captured molecules into an instrument. 

“Solvents are replaced with thermal desorption,” Gionfriddo says. “We simply heat up the probe, and because of the increase in temperature, the molecules will be transferred to the instrument.”

While EPA has standardized methods for analyzing PFAS in drinking water, wastewater, soils and biological tissues, it is still gathering feedback from the scientific community on two drafted methods for analyzing PFAS in the air, including volatile PFAS.

While many contract laboratories follow the latest guidance, Gionfriddo says, it is the role of academic labs to drive the development of precise, tailored methods to measure different classes of volatile PFAS — work that ultimately strengthens and informs regulatory standards.

“We are providing the groundwork for detecting these types of compounds that may not currently be regulated but could be in the future,” she says. “In this way, fundamental research can have a huge societal impact.”

The research was funded by the National Science Foundation (NSF) as part of Gionfriddo’s NSF CAREER Award, which she received in 2022 while at the University of Toledo. 

The study’s other co-first author is former UB postdoctoral researcher Héctor Martínez-Pérez-Cejuela. Former Toledo undergraduate student Chloe McLeod is also a co-author.