An air sampler called FM4 for per- and polyfluoroalkyl substances (PFAS) was developed for the analysis of PFAS in air. PFAS analysis with FM4 is a groundbreaking approach, which enabled the simultaneous collection and analysis of particulate and gaseous PFAS in air. With conventional filtration-based collection methods, accurate measurement is often difficult because gaseous PFAS can be adsorbed onto particles collected on the filter surface. Gaseous PFAS can change to its non-volatile form during sampling. To overcome these limitations, the FM4 was designed with an impactor that minimizes particle-gas contact and three types of sorbents, which enable simultaneous collection of ionic and neutral/volatile PFAS.
The collected PFAS is eluted with organic solvents and quantified by gas chromatography-tandem mass spectrometry (GC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Conventional activated carbons usually contain complicated pores. They have been used as trapping material for PFAS; however, complete elution of adsorbed PFAS is difficult to achieve. Therefore, a novel functional activated carbon adsorbent (GAIAC) was developed, which was used as a gas-type adsorbent. GAIAC is an innovative sorbent composed of synthetic resin fibers with optimized pore and surface activity, which enable the collection and elution of PFAS.
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