Researchers from the New Jersey Institute of Technology (NJIT) have developed a method of detecting toxic per- and poly-fluoroalkyl substances (PFAS) in food packaging, water, and soil samples in three minutes or less. The scientists believe their lab-based method could speed up efforts to address the pollution and accumulation of these “forever chemicals,” and could be useful in applications like public water quality testing. The new method provides results much more quickly than existing tests, with some taking hours for sample preparation and analysis.
The new method leverages paper spray mass spectrometry (PS-MS)—an ionization technique for analyzing the molecular composition of sample materials—which is 10–100 times more sensitive than liquid chromatography/mass spectrometry, the current standard for PFAS testing. PFAS can be ionized and rapidly detected by a high-resolution mass spectrometer, which gives a clear view of each type of PFAS present and the degree of contamination, down to a parts-per-trillion (ppt) level. For more complex matrices like soil, the researchers 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, the two techniques greatly improve the ability to detect PFAS. The new method’s limit of detection for PFAS is 1 ppt, which is equivalent to a single drop of water in 20 Olympic-sized swimming pools. When testing the method, the researchers were able to detect PFAS in one minute or less in samples of microwave popcorn paper, instant noodle boxes, fast food wrappers, and other food packaging samples. The analysis revealed traces of 11 different PFAS molecules, including common types that have been linked to cancer and immune system suppression; specifically, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), both of which have been targeted by the U.S. Environmental Protection Agency (EPA) in a proposal to establish maximum contamination levels for six types of PFAS in drinking water.