Calibration of Perfluorinated Alkyl Acid Uptake Rates by a Tube Passive Sampler in Water

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Water Quality Monitoring

Background:

• Per- and polyfluoroalkyl substances (PFAS) are widespread man-made chemicals with significant environmental and health concerns.
• Existing detection tools for passive sampling of PFAS in water are limited.
• A need exists for reliable and accessible methods for PFAS monitoring.

Purpose of the Study:

• To develop and evaluate a novel passive sampler for the integrative sampling of PFAS in water.
• To assess the performance of a microporous polyethylene tube with a hydrophilic-lipophilic balance sorbent.
• To compare laboratory and field measurements of PFAS sampling rates.

Main Methods:

• A microporous polyethylene tube sampler was designed and tested.
• Sampling rates (Rs) were predicted using partitioning-diffusion and diffusion-only models.
• Laboratory experiments were conducted at varying water flow speeds (10-60 cm s^-1) and 15 °C.
• Field deployments were used to validate laboratory findings.
• The impact of biofouling on sampler performance was investigated.

Main Results:

• Laboratory-measured sampling rates for perfluorohexanoic acid (PFHxA) and perfluorohexane sulfonate (PFHxS) were better predicted by the partitioning-diffusion model.
• Field deployment sampling rates for PFHxA fell between model estimates.
• The sampler's performance was not significantly affected by prior biofouling.
• PFAS uptake was consistent across different water flow speeds.

Conclusions:

• The developed polyethylene tube sampler is a viable tool for passive sampling of PFAS in water.
• Partitioning-derived model parameters are crucial for accurate sampling rate predictions.
• The sampler demonstrates robustness for use in diverse environmental conditions.
• This research contributes to improved methods for environmental PFAS monitoring.