Passive sampling techniques for monitoring pollutants in water Branislav Vrana, Graham A. Mills, Ian J. Allan, Ewa Dominiak, Katarina Svensson, Jesper Knutsson, Gregory Morrison, Richard Greenwood We review the state of the art in using passive sampling technology for environmental monitoring of waterborne organic and inorganic pollutants. We discuss strategies for sampler design, calibration, in situ sampling and quality-control issues, and advantages and challenges associated with passive sampling in aqueous environments. We then review typical applications of passive samplers in assessing the aquatic environment. ª 2005 Elsevier Ltd. All rights reserved. Keywords: Environmental monitoring; Environmental pollutants; Passive sampling; Sample preparation; Water analysis Abbreviations: ASV, Anodic stripping voltammetry; BTEX, Benzene, toluene, ethyl benzene and xylene; DET, Diffusion equilibrium in thin films; DGT, Diffusive gradient in thin films; GC, Gas chromatography; HPLC, High-performance liquid chromatography; LDPE, Low-density polyethylene; MESCO, Membrane-enclosed sorptive coating; nd-SPME; Negligible depletion solid-phase microextraction; NOM, Natural organic matter; OSPAR, The Convention for the Protection of the Marine Environment of the North-East Atlantic; PAH, Polycyclic aromatic hydrocarbon; PCB, Polychlorinated biphenyl; PCDD, Polychlorinated dibenzo[p]dioxin; PCDF, Polychlorinated dibenzo[p]furan; PDB, Polyethylene diffusion bag; PDBS, Passive diffusion bag sampler; PIMS, Passive integrative mercury sampler; PLM, Permeation liquid membrane; POCIS, Polar organic chemical integrative sampler; PRC, Performance reference compound; QA, Quality assurance; QC, Quality control; SBSE, Stir-bar sorptive extraction; SLM, Supported liquid membrane; SLMD, Stabilised liquid-membrane device; SPATT, Solid-phase adsorption toxin tracking; SPMD, Semi-permeable membrane device; SPME, Solid-phase microextraction; SVOC, Semi-volatile organic compound; TLC, Thin-layer chromatography; TRIMPS, Trimethylpentane-containing passive sampler; TWA, Time-weighted average; VOC, Volatile organic compound 1. Introduction It is necessary to monitor pollutants in the aquatic environment to satisfy the requirements of legislative frameworks and directives, as many of these com- pounds can pose a threat to both human health and ecosystems. A number of toxic compounds have been designated priority pollutants [e.g., those on lists of the US Environmental Protection Agency (EPA) and the Water Framework Directive of the European Union (EU)] and their measure- ment is necessary to ensure that water-quality standards are maintained. Sampling and analysis of such a broad range of organic (e.g., chlorophenols, organo- chlorine pesticides, polyaromatic hydrocarbons, polychlorinated biphenyls) and inorganic (e.g., heavy metals and some of their organo-metallic species) compounds represents an ongoing challenge to the environmental chemist. Branislav Vrana*, Ian J. Allan, Richard Greenwood School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth PO1 2DY, United Kingdom Graham A. Mills School of Pharmacy and Biomedical Sciences, University of Portsmouth, White Swan Road, Portsmouth PO1 2DT, United Kingdom Ewa Dominiak Department of Analytical Chemistry, Chemical Faculty, Gdansk University of Technology, 80 952 Gdan ´sk, G. Narutowicza 11/12, Poland Katarina Svensson, Jesper Knutsson, Gregory Morrison Water Environment Transport, Chalmers University of Technology, SE-412 96 Go ¨teborg, Sweden * Corresponding author. Tel.: +44 23 9284 2024; Fax: +44 23 9284 2070; E-mail: bran.vrana@port.ac.uk Trends in Analytical Chemistry, Vol. 24, No. 10, 2005 Trends 0165-9936/$ - see front matter ª 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.trac.2005.06.006 845 0165-9936/$ - see front matter ª 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.trac.2005.06.006 845