FIU researchers have developed a faster, more efficient method to detect forever chemicals in the water system, cutting the testing time from over six hours to just 30 minutes. These findings, which could enhance how water safety is monitored, were published in the Journal of Chromatography A.
PFAS are a group of chemicals linked to severe health risks including endocrine disruption, immune system impairments and cancer. Because these chemicals are nearly indestructible and found almost everywhere in the U.S., they are often referred to as forever chemicals and the Environmental Protection Agency (EPA) has recently enacted national regulations requiring continuous monitoring in public water systems.
The need for rapid testing is vital in places like South Florida, where drinking water is sourced from the shallow Biscayne Aquifer, which is vulnerable to surface runoff from landfills, airports, military airbase and rainwater contamination.
"Since neither wastewater treatment plants nor drinking water facilities currently treat for PFAS, contamination moves through the entire water cycle, from rainwater and surface water into groundwater and ultimately into drinking water," says Maria Guerra de Navarro, a postdoctoral associate at FIU's Institute of Environment.
Currently, water utilities are trying to adapt. Many are investing in advanced filtration technologies like activated carbon, reverse osmosis and nanofiltration membranes. However, these systems don't destroy the chemicals; instead, they concentrate them into a separate waste stream that can be difficult to safely dispose of.
In Miami-Dade County, Guerra de Navarro says groundwater wells are monitored for PFAS every four months, and the county is working to keep the ones with higher levels out of the main water supply.
FIU's new 30-minute testing method could significantly improve how these facilities track PFAS by accelerating the process. The method automates sample cleanup using online solid-phase extraction paired with high-precision testing tools to measure tiny traces of the chemicals. By using smaller samples and using less solvent, it reduces the risk of human handling errors.
The method successfully detects 39 of the 40 EPA-listed PFAS compounds. The team intentionally excluded one specific compound from the results because tracking it would have required raising the detection limits for PFOS and PFAS, the two most regulated chemicals, which was an unacceptable compromise, according to Natalia Quinete, associate professor at FIU.
From the start, the team wanted to capture smaller PFAS molecules. After testing various sample types in the lab, they proved the method could successfully analyze both small and large PFAS molecules simultaneously. The team is now working to detect even smaller molecules, which are frequently found in high concentrations in drinking water as larger PFAS molecules break down.
The research team, including Carolina Cuchimaque Lugo, a doctoral candidate in the Department of Chemistry and Biochemistry and affiliated with the Center for Aquatic Chemistry and Environment at the Institute of Environment, has already characterized PFAS in the tap water supply across multiple areas of Miami-Dade County. They are now expanding their research into human health by analyzing PFAS in human serum samples.
Before this rapid method can be widely used by water facilities, it must be certified, which requires extensive validation studies across multiple independent laboratories.
"I believe the EPA should consider incorporating this type of technology into a standard method, given the enormous national demand for PFAS monitoring under new drinking water regulations," Guerra de Navarro said.
Looking ahead, the team is developing a simpler method to measure total PFAS, not individual compounds, which could process 20 samples in a single day with minimal sample handling and more inexpensive equipment. They hope it could be used for real-time filed assessment in the future.
