Scientists around the world continue to search for microplastics and per- and polyfluoroalkyl substances (PFAS) in food, water, and other environmental media. However, the intersection of these two fields, microfluoropolymers (MFPs), has received less attention.
Now, researchers have developed a new procedure to extract and measure microplastic particles from six different fluoropolymers (Environ. Sci. Technol. 2026, DOI: 10.1021/acs.est.6c04873). For the first time, the research team detected all six species (four of them) in archived spectra of dust, airborne particles, and sediment samples. Overall MFPs accounted for approximately 2–8% of the total microplastics reflected in these spectra.
When Chu Peng and his colleagues at Nankai University started measuring MFP, they realized that little attention was paid to MFP and no reference spectra beyond polytetrafluoroethylene (PTFE) could be found. We then began working with Agilent’s China technology department to create a library of reference spectra for six fluoropolymers: PTFE, polyvinylidene fluoride (PVDF), PVDF-hexafluoropropylene copolymer (PVDF-HFP), polytrifluorochloroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE), and fluorinated ethylene propylene (FEP).
To create the reference spectrum, the researchers chose Agilent’s laser direct infrared (LDIR) spectroscopy technology, an emerging tool in microplastics research. LDIR measures the infrared absorption of polymers the same way traditional Fourier transform infrared (FTIR) spectroscopy does, except it’s faster, Peng says. This is because LDIR scans a narrower wavelength range (900 to 1800 cm-1) than FTIR, which scans the entire range from 400 to 4,000 cm-1. The CF bonds characteristic of fluoropolymers fall within that narrow wavelength range, making LDIR technology suitable for MFPs, he says.
Peng et al. prepared six different MFPs with six different granule sizes and two different fiber lengths. We also prepared a set of chemically aged MFPs to mimic the effects of weathering in the environment.
Next, we moved on to sample preparation. To be detected, the microplastics must be sufficiently exposed on the surface so that the light from the spectrometer hits them. Typically, researchers digest food, dust, and sediment samples to remove organic matter that could clump with microplastics and interfere with detection, but Peng explains that the digestion procedure must also be gentle to avoid destroying the microplastics themselves.
But MFPs are much more robust, so the researchers developed a harsher procedure that exposed them to strong acids, then strong bases, and finally organic solvents. This increased the number of MFPs by approximately 67-100%. “They basically reduced the background signal…That was a good step,” says Rainer Roman, an environmental scientist at the University of Rhode Island who was not involved in the study. Measuring all microplastics requires both traditional gentle and harsh digestion of the same sample, but Roman says the new protocol is still useful. “We can get more information from the samples we collect.”
Because LDIR instruments are commercially available, the reported method for measuring MFP should be “easily adaptable” by different research groups, says Rolf Halden, an environmental health engineer at Arizona State University who was not involved in the study. Haldane also credits Peng and his colleagues for preparing and measuring aged MFPs, as they found clear spectral differences between new and weathered MFPs. On the other hand, differences in particle size and shape did not affect the spectra.
The researchers applied a sample preparation method and used a reference library to measure PTFE MFPs prepared by cooking in a nonstick pan. Fried eggs produced 3,890 to 6,760 PTFE microplastic particles in the food, and boiling noodles produced 2,120 to 4,960 PTFE microplastic particles. Cooking with old and damaged pots yielded more MFP than cooking with new pots. For comparison, a 2023 study released millions of microplastic particles when water in a polypropylene container was microwaved for three minutes.
When the researchers analyzed an archive of microplastic spectra against MFP’s new reference spectra, they found all six types of fluoropolymers, with PTFE being the most prevalent, followed by the specialty fluoropolymer ECTFE.
Specialty fluoropolymers are highly valued in high-tech industries such as aviation, semiconductor manufacturing, and pharmaceutical manufacturing. For example, polyvinylidene fluoride (PVDF) is used to protect wires and cables like the one shown, but other materials may line the interior of containers or be used for piping, O-rings, and gaskets in demanding environments.
Credit: Shutterstock
At this stage, Haldane and Roman believe it is difficult to determine what the researchers’ combined readings mean for the environment and human health, especially because pieces of the toxicological puzzle are missing.
For PFAS researchers, who often cannot account for all the organic fluorides in dust and sediment samples, MFP could help account for missing fluorides, Roman says.
Because fluoropolymers are used extensively in electronics, Peng and his colleagues plan to sample areas around factories where electronic waste is dismantled and analyze them for use in multifunction printers. They also plan to look for MFP ingested in human stool samples.
