Passive Sampler for PFAS: PFASsive™

SiREM’s newest sampler, PFASsive™, provides a comprehensive equilibrium passive sampler to measure freely dissolved Per- and Polyfluoroalkyl Substances (PFAS) in pore water (sediment and soil) surface water and storm water. PFASsive™ can be used to provide critical data for fate and risk assessments, toxicity identification and remediation design and/or monitoring that is more representative than conventional grab samples as it quantifies contaminants only in the dissolved form.


Per- and Polyfluoroalkyl Substances (PFAS) are a large group of compounds found in aqueous film-forming foams, used for fire suppression and in everyday consumer products and are made up of a chain of linked carbon and fluorine atoms. The length and branching of the carbon-fluorine chain varies between PFAS chemicals, but as the carbon-fluorine bond is strong, PFAS persist and have the potential to undergo long range transport in the environment. Until now, effectively monitoring and measuring PFAS at low, environmentally relevant concentrations in aquatic environments was difficult.


PFASsive™ is a diffusion-based equilibrium passive sampler that has been developed and validated for targeted PFAS in sediment pore water and surface water. Upon retrieval, the water from PFASsive™ is treated as a water sample and the PFAS can be concentrated and measured using traditional EPA laboratory methods without the need for additional extraction steps required when sorbents are present.

The result is a concentration (in ng/L). As the accumulation of PFAS into the sampler is  based on molecular diffusion, the inclusion of a reverse tracer allows for the determination of the extent of equilibrium during the deployment and used to estimate the freely dissolved equilibrium concentration (Cfree) in the environment. Cfree has been shown to relate better to bioavailability, toxicity, and risk assessment models than conventional grab samples.

Experience the SiREM Difference: PFASsive™ is offered as an end-to-end service where SiREM provides the samplers, optional support for diverless deployment, analytical chemistry (in partnership with Eurofins Environmental Testing Northern California) and modelling of the final data to deliver the equilibrium concentration of PFAS. Overall, this sampler is easy to use, field evaluated and can be adapted to the growing list of PFAS chemicals of concern as both the regulations and analytical techniques evolve.

Off-the Shelf Comprehensive Solutions

  • Durable, field tested, ready-to-use samplers for use on site
  • Unique diver-less deployment and retrieval options to reduce costs and speed up field deployments
  • Inclusion of a reverse tracer allows for the equilibrium conditions of each individual sampler to be determined
  • Results provided on a dissolved phase basis (e.g., ng/L pore water), providing a superior, time averaged, representation of bioavailable concentrations

A Cost-Effective Solution

  • Improved understanding of environmental risk and mobility of target compounds as it measures only dissolved analytes and does not measure precipitated or adsorbed species
  • Potential to save money in unnecessary investigation, remediation, and management costs
  • Cost-competitive with traditional chemical measurements and there is less risk of contamination and overestimation compared to other traditional sampling techniques

Contact SiREM for more information on our pore water sampling services

pdf SiREM Sediment Pore Water Sampler for PFAS

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