Kinetic Passive Sampling: In Situ Calibration Using the Contaminant Mass Measured in Parallel Samplers with Different...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Aquatic Toxicology

Background:

• Single-phase passive samplers are widely used for bioavailable hydrophobic pollutant monitoring in aquatic environments.
• In-situ calibration is often required when samplers operate in the kinetic sampling phase.
• Performance reference compounds (PRCs) are commonly used for calibrating passive sampler exchange kinetics.

Purpose of the Study:

• To develop and evaluate a novel contaminant mass ratio (CMR) calibration approach for passive sampling.
• To assess the performance of CMR calibration as a stand-alone or complementary method.
• To determine dissolved concentrations of hydrophobic pollutants using passive samplers.

Main Methods:

• Developed a calibration method based on the contaminant mass ratio (CMR) from two passive samplers with differing thicknesses.
• Utilized silicone passive samplers to analyze polycyclic aromatic hydrocarbons (PAHs).
• Validated the CMR calibration through laboratory experiments with controlled concentrations and field studies at a stormwater retention site.

Main Results:

• Laboratory tests showed CMR-derived concentrations were within a factor of 2 of water extraction and passive dosing results.
• Field studies indicated CMR-derived concentrations varied by a factor of 1 to 3 compared to PRC calibration.
• The CMR method demonstrated reliable performance in both controlled and real-world aquatic conditions.

Conclusions:

• The contaminant mass ratio (CMR) calibration is a viable method for determining dissolved pollutant concentrations.
• CMR calibration can be effectively used independently or in conjunction with existing calibration techniques.
• This approach enhances the accuracy and reliability of kinetic passive sampling for hydrophobic contaminants.