Assessment of silicone polymer composites for environmental forensic applications: a proof of concept study

This study evaluates the use of polydimethylsiloxane polymer composites (PDMS, Fe-PDMS) as a passive sampling media to preconcentrate analytes found in environmental settings. Samplers were made using commercially available silicone products. The composite samplers were assessed for their sorption properties using Atrazine and Irgarol 1051 as model compounds. The initial study assessed the utility of PDMS sheets as adsorption material by following analyte depletion from spiked water samples by solid-phase microextraction gas chromatography/mass spectrometry (GC/MS). Follow-up studies conducted at high and low concentrations using lab manufactured iron- PDMS rods (Fe-PDMS) showed effective uptake at differential rates from concentrations ranging between 1 μg/L and 10 μg/L. Adsorption mechanism was reversible, and compounds were recovered from the exposed materials and analyzed by liquid-liquid extraction-GC/MS. Both composites showed better affinity for Irgarol 1051, 100% removal, than for Atrazine, 30% removal, likely representing their K(OW) differences, 3.6 and 2.6, respectively. This "proof of concept" study demonstrates the positive implications for the use of silicon polymer composites as a monitoring tool for environmental forensic purposes.