Comparison of five integrative samplers in laboratory for the monitoring of indicator and dioxin-like polychlorinated biphenyls in water

Abstract

This study aimed at evaluating and comparing five integrative samplers for the monitoring of indicator and dioxin-like polychlorinated biphenyls (PCBs) in water: semi-permeable membrane device (SPMD), silicone rubber, low-density polyethylene (LDPE) strip, Chemcatcher and a continuous-flow integrative sampler (CFIS). These samplers were spiked with performance reference compounds (PRCs) and then simultaneously exposed under constant agitation and temperature in a 200 L stainless steel tank for periods ranging from one day to three months. A constant PCB concentration of about 1 ng·L(-1) was achieved by immersing a large amount of silicone rubber sheets ("dosing sheets") spiked with the target PCBs. The uptake of PCBs in the five samplers showed overall good repeatability and their accumulation was linear with time. The samplers SPMD, silicone rubber and LDPE strip were the most promising in terms of achieving low limits of quantification. Time-weighted average (TWA) concentrations of PCBs in water were estimated from uptake of PCBs using the sampling rates calculated from the release of PRCs. Except for Chemcatcher, a good agreement was found between the different samplers and TWA concentrations ranged between 0.4 and 2.8 times the nominal water concentration. Finally, the influence of calculation methods (sampler-water partition coefficients, selected PRCs, models) on final TWA concentrations was studied.

Overview of the Chemcatcher® for the passive sampling of various pollutants in aquatic environments Part A: Principles, calibration, preparation and analysis of the sampler

“…Only a few studies [34,35,61,69] were conducted with the objective of comparing the performances of these passive samplers, in particular to investigate the various uptake kinetics and sampling rates [34,61]. Indeed, R s values will differ because of the intrinsic characteristics of each device (materials for the receiving phase and membrane, diffusion and accumulation mechanisms and sampling area).…”

“…3. Static with partition controlled delivery -In Jacquet et al [34], contamination by polychlorobiphenyls (PCB) was regulated by immersing a spiked solid-phase sorbent (silicone rubber dosing sheets) which equilibrated with exposure water. Chemcatcher Table 1 Calibration methodology (design, duration, tested parameters, matrix) (greenchecks indicate applied and red crosses unused parameters).…”

Low density polyethylene (LDPE) passive samplers for the investigation of polychlorinated biphenyl (PCB) point sources in rivers

“…The in-situ enrichment of contaminants in samplers over long-term exposure enables to achieve limits of quantitation (LOQ) low enough to measure hydrophobic contaminants (such as PCBs) in water (Vrana et al, 2005a;Zabiegała et al, 2010;Jacquet et al, 2014). In addition, the use of integrative passive samplers enables to sequester pollutants from episodic pollution.…”

“…These advantages make passive sampling a method of choice to investigate PCB sources in rivers. The use of traditional grab sampling would require sophisticated analytical methods to be sensitive enough and would not take into account variations in concentrations (Jacquet et al, 2014). The use of automated sampling devices would not be practicable since it necessitates secured sites with a power supply.…”

“…As the pollution at the moment of sampling needs to be determined, PCB measurements have to be carried out in water rather than in sediments (which reflect historical pollution and are mobile) or in fishes (which move). However, due to their hydrophobicity, PCBs are present at very low concentrations in the dissolved phase, typically in the ng L À1 to pg L À1 range (Jacquet et al, 2014). Therefore, the tool selected to develop the methodology must be sensitive enough to capture low PCB concentrations in river water.…”