Comparing polyethylene and polyoxymethylene passive samplers for measuring sediment porewater concentrations of polychlorinated biphenyls: Mutual validation and possible correction by polymer-polymer partition experiment

Abstract

Two sediment passive samplers, polyethylene (PE) and polyoxymethylene (POM), were compared and mutually validated for measuring freely dissolved concentrations (C) of polychlorinated biphenyls (PCBs) in sediment porewater. PE and POM strips in commonly used dimensions (30 and 76 μm in thickness, respectively) were exposed to sediment slurries for 28 d. The C values calculated using literature polymer-water partition coefficients were consistently higher for PE than for POM by a factor of 2 on average. Time series experiments over 96 d show that 28 d are sufficient for attaining partition equilibrium of PCBs for PE, whereas even 96 d may not be enough for POM. To gain additional insight, POM and PE strips were co-exposed to bovine serum albumin suspension spiked with PCBs. The POM/PE concentration ratios increased over 56 d, and the ratios at 28 d were in agreement with the POM-to-PE ratios of PCB concentrations from the 28-d sediment slurry experiments. This agreement suggests that the use of apparent POM-water partition coefficients (i.e., non-equilibrium concentration ratios) suitable for a 28-d exposure to sediment slurries may correct the non-attainment of equilibrium and could provide more accurate C values.

Comprehensive Multi-compartment Sampling for Quantification of Long-Term Accumulation of PAHs in Soils

“…The partition coefficients for PAHs between PE and air or water are well known and available in the literature. , Studies on ex situ batch tests using passive samplers in soil and sediment slurries report equilibration within 14 or 28 days of constant mixing. , Detailed studies on mass transfer of phenanthrene to PE microplastics in water show fast equilibration, for example, of 260 μm sized particles within a few hours . While uptake kinetics on pure passive sampling materials are fast and follow classical mass-transfer relationships, the desorption kinetics from soil particles is not well known, especially in heterogeneous materials.…”

Evaluation of passive sampling polymers and nonequilibrium adjustment methods in a multiyear surveillance of sediment porewater PCBs

“…Another group observed a similar factor‐of‐2 discrepancy between the 2 polymers’ measurements in ex situ sediments. They proposed the use of a PE/POM correction factor in lieu of PRCs but noted that POM had not fully equilibrated even after 96 d in their experimental systems (Endo et al ). Considering ease of use, equilibration rate, and reproducibility of PRC desorption, PE proved to be the most effective among the sampling materials evaluated in the present study.…”

Chasing equilibrium passive sampling of hydrophobic organic compounds in water

“…For estimation of C w or other related measures of chemical activity in water for very hydrophobic HOC the kinetic method using PRCs remains the method of choice, as outlined in the available guidance document (Smedes and Booij, 2012) (David and Sandra, 2007), e (Booij et al, 2007), f (Roll and Halden, 2016), g (Fernandez et al, 2009), h (Witt et al, 2013), i (Cornelissen et al, 2008, j (Jonker et al, 2018), k (Endo et al, 2017), l (Greenberg et al, 2014) Figure 1 Mounting silicone passive sampler in a deployment frame for exposure in water at site S1A (left) and in the dynamic passive sampling device for deployment at all remaining sites (right). ) absorbed by two co-deployed silicone passive samplers ALT and SSP with film thicknesses of 500 and 125 µm, respectively, plotted versus log K ow .…”