Using Polydimethylsiloxane (PDMS) Pellets to Create an Absorption Model for the Determination of Equilibrium Concentrations of Dissolved Contaminants in the Aquatic Environment.

Abstract

Polydimethylsiloxane (PDMS) is a polymer material with high absorptive properties increasingly used as a passive environmental sampler for persistent organic compounds. However, the partitioning behavior of hydrophobic chemicals to PDMS remains largely unknown. Organochlorines (OCs) and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants of great concern due to their persistence and potential toxic effects on humans and animals. In this study, the affinity of 20 OCs and 25 PAHs for commercially available PDMS pellets was determined to assess their effectiveness as passive samplers. Experiments were conducted to estimate the absorption rates (k) and equilibrium concentrations, demonstrating that 16 OCs and 21 PAHs were efficiently absorbed by PDMS, while others remained dissolved in water. A model has been proposed to predict dissolved concentrations in water based on the Kow of the compound, suggesting that PDMS is a suitable passive sampler for these compounds.