Effects of Environmentally Relevant Concentration Exposure Profiles on Polar Organic Chemical Integrative Sampler...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Environmental Science

Background:

• Passive sampling devices like the Polar Organic Chemical Integrative Sampler (POCIS) offer advantages over traditional methods for environmental monitoring.
• Accurate quantification of time-weighted average (TWA) concentrations using POCIS relies on the stability and robustness of their sampling rates.
• Understanding how varying chemical exposures affect POCIS performance is crucial for reliable environmental data collection.

Purpose of the Study:

• To investigate the impact of constant and pulsed pesticide concentrations on POCIS sampling rates.
• To assess the effect of these varying exposures on the integrative performance of POCIS.
• To determine the range of environmentally relevant concentrations for which POCIS remains accurate.

Main Methods:

• Conducted five independent 21-day experiments exposing POCIS devices to 12 pesticides.
• Utilized constant concentrations (3–60 μg/L) and pulsed concentrations (peaks 5–150 μg/L, TWA 3–92 μg/L).
• Analyzed POCIS sampling rates and integrative regime performance under different exposure scenarios.

Main Results:

• No significant differences in POCIS sampling rates were observed between constant and pulsed concentration exposures for corresponding TWA concentrations.
• POCIS demonstrated a consistent ability to operate in an integrative regime across tested concentrations.
• Loss of linearity occurred in some replicates at high pulsed concentrations, potentially linked to extraction protocols and sorbent capacity.

Conclusions:

• POCIS sampling rates are robust to variations in pesticide concentration, supporting their use for TWA measurements.
• The integrative performance of POCIS is reliable within the studied range of environmental concentrations.
• Potential underestimation of sorbed mass can occur at high concentrations due to extraction limitations, necessitating careful protocol evaluation.