title: An in-situ assessment of low-density polyethylene and silicone rubber passive samplers using methods with and without performance reference compounds in the context of investigation of polychlorinated biphenyl sources in rivers.
abstract: This study firstly aims to assess the field performances of low density polyethylene (LDPE) and silicone rubber (SR) samplers for the monitoring of polychlorinated biphenyls (PCBs) in water regarding the uptake, the sampling rate (RS) estimated by using performance reference compounds (PRCs) and the time-weighted average (TWA) concentrations. The second aim is to evaluate the efficiency of these samplers to investigate PCB sources (localization and imputation steps) using methods with and without PRCs to correct for the impact of water velocity on the uptake. Samplers spiked with PRCs were deployed in the outfalls of two PCB sources and at 8 river sites situated upstream and downstream of the outfalls. After 6weeks, the uptake of PCBs in the linear phase was equivalent in LDPE and SR but 5 times lower in LDPE for PCBs approaching equilibrium. PRC-based RSand water velocity (0.08 to 1.21ms-1) were well correlated in river (LDPE: R2=0.91, SR: R2=0.96) but not in outfalls (higher turbulences and potential release of PRCs to air). TWA concentrations obtained with SR were slightly higher than those obtained with LDPE (factor 1.4 to 2.6 in river) likely because of uncertainty in sampler-water partition coefficient values. Concentrations obtained through filtration and extraction of water samples (203L) were 1.6 and 5.1 times higher than TWA concentrations obtained with SR and LDPE samplers, respectively. PCB sources could efficiently be localized when PRCs were used (increases of PCB loads in river) but the impact of high differences of water velocity was overcorrected (leading sometimes to false positives and negatives). Increases of PCB loads in the river could not be entirely imputed to the investigated sources (underestimation of PCBs contributing to the load increases). A method without PRCs (relationship between uptake and water velocity) appeared to be a good complementary method for LDPE.
authors.affiliation: School of Criminal Sciences, University of Lausanne, Batochime building, 1015 Lausanne, Switzerland. Electronic address: nicolas.estoppey@unil.ch.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Estoppey
authors.affiliation: School of Criminal Sciences, University of Lausanne, Batochime building, 1015 Lausanne, Switzerland.
authors.forename: Adrien
authors.initials: A
authors.lastname: Schopfer
authors.affiliation: Central Environmental Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 2, 1015 Lausanne, Switzerland.
authors.forename: Camille
authors.initials: C
authors.lastname: Fong
authors.affiliation: School of Criminal Sciences, University of Lausanne, Batochime building, 1015 Lausanne, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Delémont
authors.affiliation: Central Environmental Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 2, 1015 Lausanne, Switzerland.
authors.forename: Luiz F
authors.initials: LF
authors.lastname: De Alencastro
authors.affiliation: School of Criminal Sciences, University of Lausanne, Batochime building, 1015 Lausanne, Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Esseiva
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D020959:Polyethylene; D045483:Rivers / Q000737:chemistry*; D012826:Silicone Elastomers; D013557:Switzerland; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D012826:Silicone Elastomers; D014874:Water Pollutants, Chemical; D020959:Polyethylene; D011078:Polychlorinated Biphenyls
keywords: LDPE; PCB; PRC; SR; Sampling rate (R(S)); Time-weighted average (TWA) concentration