title: Metal measurement in aquatic environments by passive sampling methods: Lessons learning from an in situ intercomparison exercise.
abstract: Passive sampling devices (PS) are widely used for pollutant monitoring in water, but estimation of measurement uncertainties by PS has seldom been undertaken. The aim of this work was to identify key parameters governing PS measurements of metals and their dispersion. We report the results of an in situ intercomparison exercise on diffusive gradient in thin films (DGT) in surface waters. Interlaboratory uncertainties of time-weighted average (TWA) concentrations were satisfactory (from 28% to 112%) given the number of participating laboratories (10) and ultra-trace metal concentrations involved. Data dispersion of TWA concentrations was mainly explained by uncertainties generated during DGT handling and analytical procedure steps. We highlight that DGT handling is critical for metals such as Cd, Cr and Zn, implying that DGT assembly/dismantling should be performed in very clean conditions. Using a unique dataset, we demonstrated that DGT markedly lowered the LOQ in comparison to spot sampling and stressed the need for accurate data calculation.
authors.affiliation: Irstea, UR MALY, Freshwater Systems, Ecology and Pollution Research Unit, 5 rue de la Doua, CS 70077, F-69626, Villeurbanne, France. Electronic address: aymeric.dabrin@irstea.fr.
authors.forename: A
authors.initials: A
authors.lastname: Dabrin
authors.affiliation: BRGM, 3 Avenue C. Guillemin, BP 36009, Orléans Cedex 2, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Ghestem
authors.affiliation: Irstea, UR HBAN, F-92163, Antony, France.
authors.forename: E
authors.initials: E
authors.lastname: Uher
authors.affiliation: Ifremer, Département Biogéochimie et Ecotoxicologie, B.P. 330 Zone Portuaire de Brégaillon, 83507, La Seyne/mer cedex, France.
authors.forename: J-L
authors.initials: JL
authors.lastname: Gonzalez
authors.affiliation: Norwegian Institute for Water Research (NIVA), Gaustalleen 21, O349, Oslo, Norway.
authors.forename: I J
authors.initials: IJ
authors.lastname: Allan
authors.affiliation: Università degli Studi di Cagliari, Cagliari, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Schintu
authors.affiliation: AZTI-Tecnalia, Marine Research Division, Herrera kai, Portualdea z/g, Pasaia, 20110, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Montero
authors.affiliation: Cefas, Centre for the Environment, Fisheries and Aquaculture Science, Lowestoft Laboratory, Lowestoft, United Kingdom.
authors.forename: J
authors.initials: J
authors.lastname: Balaam
authors.affiliation: ALS Scandinavia, Box 511, SE-183 25, Taby, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Peinerud
authors.affiliation: Irstea, UR MALY, Freshwater Systems, Ecology and Pollution Research Unit, 5 rue de la Doua, CS 70077, F-69626, Villeurbanne, France.
authors.forename: C
authors.initials: C
authors.lastname: Miège
authors.affiliation: Irstea, UR MALY, Freshwater Systems, Ecology and Pollution Research Unit, 5 rue de la Doua, CS 70077, F-69626, Villeurbanne, France.
authors.forename: M
authors.initials: M
authors.lastname: Coquery
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D008670:Metals / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical
keywords: Blank; Coastal waters; Continental waters; DGT; Uncertainty