Accelerated solvent extraction (ASE) for purification and extraction of silicone passive samplers used for the monitoring of organic pollutants

Abstract

Silicone passive samplers have gained an increasing attention as single-phased, practical and robust samplers for monitoring of organic contaminants in the aquatic environment in recent years. However, analytical challenges arise in routine application during the extraction of analytes as silicone oligomers are co-extracted and interfere severely during chemical analyses (e.g. gas chromatographic techniques). In this study, we present a fast, practical pre-cleaning method for silicone passive samplers applying accelerated solvent extraction (ASE) for the removal of silicone oligomers prior to the water deployment (hexane/dichloromethane, 100 °C, 70 min). ASE was also shown to be a very fast (10 min) and efficient extraction method for non-polar contaminants (non-exposed PRC recoveries 66–101 %) sampled by the silicone membrane. For both applications, temperature, extraction time and the solvent used for ASE have been optimized. Purification of the ASE extract was carried out by silica gel and high-pressure liquid size exclusion chromatography (HPLC-SEC). The silicone oligomer content was checked by total reflection X-ray fluorescence spectroscopy (TXRF) in order to confirm the absence of the silicone oligomers prior to analysis of passive sampler extracts. The established method was applied on real silicone samplers from the North- and Baltic Sea and showed no matrix effects during analysis of organic pollutants. Internal laboratory standard recoveries were in the same range for laboratory, transport and exposed samplers (85–126 %).

Applications for Passive Sampling of Hydrophobic Organic Contaminants in Water—A Review

“…[299] [306,307] Calibration tank Various SR-water partition coefficients were determined for various HOCs through cosolvent methods (water/methanol) and compared to log Kow. [14,217] Calibration tank PAHs; PCBs; pesticides Calculation of new, and recalculation of reported, polymer water partition coefficients for SPMD and SR, through cosolvent, lipid and aqueous exposures in batch experiments, to facilitate conversion of equivalent analyte concentrations between phases with only partition coefficients.…”

Evaluating organochlorine pesticide residues in the aquatic environment of the Lake Naivasha River basin using passive sampling techniques

“…There are various kinds of non-polar passive samplers, which have been used for evaluating organic contaminants in aquatic environments (Brockmeyer et al 2015 ). Passive samplers trap the pollutants in a kinetic or equilibrium diffusion, in which the whole process including selective analyte, isolation, and pre-concentration occurs simultaneously (Vrana et al 2005 ).…”

Silicone Wristbands in Exposure Assessment: Analytical Considerations and Comparison with Other Approaches

“…A raw silicone sampler contains oligomers that will likely interfere during the post-deployment analysis [ 33 , 34 , 35 ]. Indeed, in a study by Rusina et al [ 29 ], the release of oligomers after exhaustive extraction with ethyl acetate for ten silicone rubbers was tested.…”