PARENT SESSION
WA4 - Passive Samplers for POPs
Chair: Harner, Tom1, 1 Environment Canada, Downsview, ON
Co-chair: Jones, Kevin2, 2 Lancaster University, Lancaster, LA1 4YQ
8:00 AM to 12:00 PM - Wednesday, 20 November 2002
Room Ballroom F
(521) Solid phase microextraction: passive sampling technique to estimate body residues of organic chemicals.
Leslie, Heather*,1,2, Kraak, Michiel2, Hermens, Joop1, 1 Utrecht University, Utrecht, The Netherlands2 University of Amsterdam, Amsterdam, The Netherlands
ABSTRACT- Several passive sampling methods are available for estimating the potential bioconcentration of industrial organic contaminants which are present and often persistent in the environment. Biomimetic solid phase microextraction (SPME) using polymer-coated fibers is such a technique. Due to their small size and relatively fast kinetics SPME fibers can be employed for laboratory analysis of environmental samples. SPME fibers exposed to contaminated samples accumulate organic chemicals by passive uptake. The partitioning from the aqueous phase to the tiny fiber coating volume proceeds with negligible depletion of the dissolved concentration, i.e. without disturbing the bound fraction, which is considered unavailable to contribute to bioconcentration in the field. Two different polymer coatings have been tested to find the preferred surrogate phase for simulating the bioconcentration process, and to explore the influence of different chemical and polymer properties on the partitioning. The fiber concentrations measured were related to aquatic invertebrate body residues, which at critical levels, lead to toxicity. We have shown that while the absolute chemical concentrations in a polymer are not identical to the concentrations in the lipid phases of organisms, they can be calibrated to give good estimates of the body residues of the compounds detected in the sample. Thin, disposable SPME fibers accumulate relatively fast, so they can be added to toxicity tests alongside the test organisms to mimic uptake by biota. Potential use of this SPME sampling method in complex matrices (e.g. sediment, soil, protein) is discussed with regard to experimental conditions. While other sampling techniques are well-suited to field studies, the biomimetic SPME sampling method is an important option for laboratory studies aimed at investigating partitioning behaviour and potential bioconcentration of organic contaminants which have the tendency to persist and accumulate in organisms in the environment.
Key words: biomimetic sampling, body residues, organic chemicals, bioavailability