| Abstract
| - Polymer coated glass fibers were applied as disposablesamplers to measure dissolved concentrations of persistentand bioaccumulative pollutants (PBPs) in sedimentporewater. The method is called matrix solid-phasemicroextraction (matrix-SPME), because it utilizes theentire sediment matrix as a reservoir for an equilibriumextraction: a glass fiber with a 15 μm coating of poly(dimethylsiloxane) (PDMS) was placed in a sediment sampleuntil the PBPs reached their equilibrium distributionbetween the PDMS and the sediment matrix (1−30 days).PBP concentrations in the PDMS were determined bygas chromatography, and they were divided by PDMS waterpartition coefficients to derive at dissolved porewaterconcentrations. This approach was applied to measureporewater concentrations of spiked as well as field sediment,and several hydrophobic organic substances (log KOW 5.2−7.5) were measured with high precision in the pg tong/L range. Simple equilibrium partitioning is the basis forthe substantial concentration factors that are built intomatrix-SPME and for the low demands in materials andoperation time. Matrix-SPME was in this study directed atthe determination of dissolved porewater concentrationsin sediment, and it is further expected to be applicable toother environmental media, to field sampling, and to thesensing of fugacity.
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