Per- and Polyfluoroalkyl Substance (PFAS) Core Technology Team

Media

Sources/Usage: Public Domain. View Media Details

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that can be challenging to detect in environmental media due to their unique properties and characteristics. The PFAS Core Technology Team (CTT) is comprised of four nationwide laboratories focusing on developing optimal extraction and analytical techniques for measuring PFAS in various environmental media, as well as elucidating total PFAS burdens in the environment. The PFAS CTT utilizes a variety of analytical approaches including target and non-target analysis, extractable organic fluorine (EOF), and the total oxidizable precursor assay (TOPA). These approaches collectively enhance the understanding of PFAS contamination in the environment and can yield valuable insights for ecosystem health, site characterization and source identification.

Key Analytical Capabilities:

• Targeted Analysis: The targeted approach quantifies a defined list of known analytes and includes both liquid and gas chromatography.
• Non-targeted analysis: The non-targeted approach involves analyzing samples for PFAS compounds that are not part of a predefined list, allowing for the detection of emerging or previously uncharacterized substances.
• Suspect screening: This approach combines target and non-target methods to identify and quantify PFAS compounds based on their chemical structure, focusing on compounds that resemble known PFAS.
• Passive Samplers: The Polar Organic Chemical Integrative Sampler (POCIS) collects PFAS in the dissolved phase, providing an estimate of bioavailable PFAS that aquatic organisms may encounter.
• Electrochemical PFAS Sensors: This approach employs different sensors (molecularly imprinted polymers (MIP) and the metal organic framework (MOF)) for detecting PFAS. 
• Optical Property Measurements as Proxies for PFAS: This approach uses multi-probe sensors to measure the fluorescence of PFAS to develop statistical models for predicting PFAS concentrations.
• Methods in development: 
  • High-Sensitivity Extractable Organic Fluorine (EOF): EOF analysis measures the total fluorine content in a sample, providing an estimate of the presence of all fluorinated compounds, including those not specifically identified.
  • Total Oxidizable Precursor Assay (TOPA): TOPA is an analytical method used to quantify PFAS precursors in environmental samples. This assay involves oxidizing PFAS precursors, often not detected by traditional methods, into measurable terminal PFAS compounds. By converting these precursors into their more stable forms, TOPA provides a more comprehensive understanding of PFAS contamination and its potential sources.

                                                                                           PFAS CTT Partners: 

Media

Sources/Usage: Public Domain. View Media Details

• Drinking Water and Wastewater Infrastructure Science Team
• Ecologically-Driven Exposure Pathways Science Team
• Energy Integrated Science Team
• Fishing and Hunting Integrated Science Team
• Food Resources Lifecycle Integrated Science Team
• Immunomodulation Science Team
• Per- and Polyfluoroalkyl substances (PFAS) Integrated Science Team
• Other Core Technology Teams (CTT)
• Other USGS Mission Areas
• EPA
• NIEHS
• NIH
• US FWS
• USDA
• DOD