York University atmospheric chemistry researchers have developed a system to detect gaseous fluorine for atmospheric PFAS quantification. While researchers have known for decades that a large amount of per- and polyfluoroalkyl substances (PFAS) existed in the atmosphere, quantifying the extent of the contamination has proven difficult.
In the research, published in Environmental Science & Technology Letters, the team measured the amount of fluorine released using chemicals such as fluorosurfactant liquids. The team conducted these tests both within the laboratory and outside, ultimately finding that 65 to 99 percent of the lab fluorine was not accounted for while outside it was around 50 percent.
“I expected missing fluorine, but I didn’t expect it to be so much. This new technique can measure all fluorinated things in the atmosphere, which has never been done before and shows the majority cannot be accounted for using our usual measurements,” said Professor Cora Young, an atmospheric chemist in York’s Faculty of Science. “It’s important as missing gaseous fluorine accounts for a huge part of airborne PFAS compared to what we actually measure at the moment, which means a lot of the PFAS aren’t being detected.”
Since most PFAS compounds include fluorine bonded with carbon, testing for fluorine offers a simpler method for analysis versus measuring all PFAS contaminants individually. While methods exist to analyze fluorine content in soil and water, the team needed to adapt a gaseous chlorine method they previously developed to capture fluorine in its gaseous form.
“Much of the focus of research on PFAS was on what's happening in the water in the soil, not as much on what happens in the air, despite the fact that these fluorinated compounds, by the nature of their chemical properties and that they are in so many commercial products, are more likely to go into the air,” added Young.