Furthering the Capabilities of Diffusive-Gradient Passive Samplers for Per- and Polyfluoroalkyl Substances

Per-
and polyfluoroalkyl substances (PFAS) are chemical pollutants
of growing concern for many stakeholders. Due to their ubiquity, persistence
in the environment, and potential for toxicity at low environmental
concentrations, it is necessary to have convenient and reliable methods
to measure PFAS in natural waters. Passive sampling methods (in situ
preconcentration of PFAS) may be suitable for monitoring situations.
One passive sampling design successfully employed for other, well
studied contaminants (e.g., methylmercury) is the diffusive gradient
in thin film sampler (DGT). However, the application of DGT for PFAS
requires development and validation. Here, we iterate on previous
PFAS-DGT studies by introducing a redesigned diffusive gradient sampler
for PFAS in water and show that it reliably measures 25 PFAS in water,
consistent with diffusion theory. Diffusion and whole-sampler uptake
rates consistently agreed with model predictions within ±50%
relative difference, including when tested at cold temperature (5
°C). In field and laboratory deployments, DGT samplers measured
PFAS concentrations within ±23% of grab sample results on average
in each casebetter performance than codeployed microporous
polyethylene tube passive samplers. Based on the evidence in this
study, the DGT passive sampler is a promising tool for consistently
and accurately passively sampling PFAS in natural waters.