Development of an air sampling method for quantifying 12 legacy and emerging PFAS with the OSHA Versatile Sampler...

This study evaluates an air sampling method for quantifying twelve legacy and emerging per- and polyfluoroalkyl substances (PFAS) with the OSHA Versatile Sampler (OVS) tube. We expanded the application of the OVS tube beyond perfluorooctanoic acid (PFOA) by adding multiple acidic PFAS classes including perfluorocarboxylic acids (PFCAs), perfluorosulfonic acids (PFSAs), undecafluoro-2-methyl-3-oxahexanoic acid (HFPO-DA, commercially known as GenX), and the sodium salt of 4,8-dioxa-3H-perfluorononanoic acid (DONA-Na). A two-step spiking approach was employed to introduce PFAS to the OVS tube. Non-volatile PFSAs and DONA-Na were statically spiked onto glass fiber filters and XAD-2 media, and then semi-volatile PFCAs and HFPO-DA were introduced via vapor generation with active airflow from spikes applied to the polytetrafluoroethylene (PTFE) retaining ring within the OVS tube. PFAS were quantified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with calibration ranges of 0.5-200.0 ng/mL (1.0-200.0 ng/mL for HFPO-DA) and analytical limits of detection (LODs) of 0.1-1.5 ng/mL (equivalent to air sampling LODs of 0.4-6 ng/m³). Extraction of OVS media with methanol yielded mean recoveries of 97.1-100.1 %. Spiked PFAS compounds at air concentrations of 0.1-20 μg/m³ (0.1-5 μg/m³ for DONA-Na) were retained on the OVS tube over a 28-day storage period at 23 °C (mean recoveries: 91-103 %) with breakthrough <5 % for all analytes. These findings establish the OVS tube as a reliable sampling device for monitoring occupational air exposures to a broader range of PFAS compounds, providing critical support for health risk assessment and exposure mitigation in workplace environments.