Equilibrium sampling of hydrophobic organic contaminants in sediments

Abstract

Passive samplers are useful novel tools for assessing contaminant exposure and evaluating its potential for adverse environmental effects. Passive equilibrium samplers enable the quantification of freely dissolved concentrations (Cfree) of organic contaminants in sediments. Cfree allows a direct assessment of (1) contaminant exchange and equilibrium status between sediment and overlying water, (2) benthic bioaccumulation, and (3) potential toxicity to benthic organisms. Thus, the use of equilibrium samplers improves the mechanistic understanding of fate and transport processes in sediments. Equilibrium samplers can be applied for hazard and risk assessment and management of contaminated sediments of aquatic environments.

The objective of this chapter is to provide introductory guidance on the use of passive equilibrium samplers for sediments contaminated with hydrophobic organic contaminants, whereby three different approaches are recommended: (1) silicone-coated glass jars, (2) SPME fibers that can be used ex situ with sediments that had been sampled in the field, and (3) SPME fibers that can be exposed directly in the field (in situ) when they are installed in a protective housing that is buried in the sediment. After reading this chapter, users will have a fundamental understanding of equilibrium passive samplers and their potential applications to sediments.