Chemcatcher

Chemcatcher® is a passive sampling device currently being used throughout the world to measure time-weighted average (TWA) ^[1] concentrations of organic and heavy metal pollutants in water. The Chemcatcher® concept was developed^{[2] [3]} by Professors Richard Greenwood and Graham Mills at the University of Portsmouth, together with colleagues from Chalmers University of Technology, Sweden. The device is patented^{[4] [5]} in a number of countries and the name is a registered trademark in the United Kingdom^[6].

The sampler comprises a low-cost, three component, water-tight PTFE body into which the appropriate 47 mm 3M Empore™ receiving phase disk (e.g. C18, styrene-divinylbenzene, chelating resin) is inserted depending on the class of pollutants being measured^{[7][8][9][10][11][12][13][14]}. The disk can be covered with a thin diffusion limiting membrane (e.g. low-density polyethylene, polyethersulphone) depending on the application the device is being used for. The sampler can be deployed in the field for extended periods of time ranging from days to weeks. The specific pollutants of interest are sequestered by the samplers and these are retained on the receiving phase disk. After retrieval from the environment the pollutants are eluted from the disk and analysed in the laboratory using conventional instrumental methods. In order to obtain TWA concentrations the sampler must first be calibrated in the laboratory so as to ascertain the uptake rate (usually measured as the volume of water cleared per unit time i.e. L/h for the analyte) of the pollutant of interest. The Chemcatcher® has been used in a range of aquatic environments; however, most work to date has been in monitoring the TWA concentrations of priority and emerging pollutants surface waters^[15][16][17].

The use of passive sampling devices^[18][19], such as the Chemcatcher®, have a number of advantages over the use of spot or bottle sampling for monitoring pollutants in the aquatic environment. The latter technique gives only an instantaneous concentration of the pollutant as the specific time of sampling. Passive samplers, depending on their mode of use can give either the TWA or equilibrium concentration of the pollutant over the deployment period. The measurement of TWA concentrations give a better indication of the long-term environmental conditions and enables improved risk assessment. Such devices have potential roles in monitoring programmes such as those underpinning the European Union’s Water Framework Directive^[20] and Marine Strategy Framework Directive. An ISO standard concerning the use of passive samplers for the determination of priority pollutants in surface waters is available for end users of this technology^[21].

More information on the Chemcatcher® passive sampling device and ongoing research activities can be found at http://www.port.ac.uk/research/chemcatcher/

References

1. ^ see entry on Permissible exposure limit for contextual definition of TWA
2. ^ Kingston, J; Greenwood R, Mills GA, Morrison, GM and Björklund-Persson, L (2000). "Development of a novel passive sampling system for the timed-averaged measurement of a range of organic pollutants in aquatic environments". J Environ Monit 2: 487–495. http://pubs.rsc.org/en/content/articlepdf/2000/em10.1039/b003532g. 
3. ^ Björklund, L; Morrison, GM, Friemann, J-U, Kingston, J, Mills GA and Greenwood, R. (2001). "Diffusional behaviour of metals in a passive sampling system for monitoring aquatic pollution". J Environ Monit 3: 639–645. http://pubs.rsc.org/en/content/articlepdf/2001/EM/B107959J. 
4. ^ Greenwood, R; Kingston J, Mills GA, Morrison G and Björklund-Persson L. "Design and application of passive sampling device for the timed-average measurement of organic compounds in the aquatic environment". UK Patent No 2353860: Granted February 2004. 
5. ^ Greenwood, R; Kingston J, Mills GA, Morrison G and Björklund-Persson L. "Design and application of passive sampling device for the timed-average measurement of organic compounds in the aquatic environment". US Patent Application No. 10/069351: Granted June 2006. 
6. ^ Intellectual Property Office. "Case details for Trade Mark 2450451". http://www.ipo.gov.uk/domestic?domesticnum=2450451. Retrieved 21 September 2011. 
7. ^ Vrana, B; Mills GA, Greenwood R, Knutsson J, Svensson K and Morrison GM (2005). "Performance optimisation of a passive sampler for the monitoring of hydrophobic organic pollutants in water". J Environ Monit 7: 612–620. http://pubs.rsc.org/en/Content/ArticleLanding/2005/EM/b419070j. 
8. ^ Vrana, B; Mills GA, Dominiak E and Greenwood R (2006). "Calibration of the Chemcatcher passive sampler for the monitoring of priority organic pollutants in water". Environ Pollution 142: 333–343. http://www.sciencedirect.com/science/article/pii/S026974910500518X. 
9. ^ Vrana, B; Mills GA, Kotterman M, Leonards P, Booij K and Greenwood R (2007). "Modelling and field application of the Chemcatcher passive sampler calibration data for the monitoring of hydrophobic organic pollutants in water". Environ. Pollution 145: 895–904. http://www.sciencedirect.com/science/article/pii/S0269749106003216. 
10. ^ Allan, IJ; Knutsson J, Guigues N, Mills GA, Fouillac AM, and Greenwood R (2007). "Evaluation of the Chemcatcher and DGT passive samplers for monitoring metals with highly fluctuating water concentrations". J Environ Monit 9: 672–681. http://pubs.rsc.org/en/content/articlelanding/2007/em/b701616f. 
11. ^ Aguilar-Martínez, R; Greenwood R, Mills GA, Vrana B, Palacios-Corvillo MA and Gómez-Gómez MM (2008). "Assessment of Chemcatcher passive sampler for the monitoring of inorganic mercury and organotin compounds in water". International J Environ Anal Chem 88: 75–90. http://eprints.port.ac.uk/1158/. 
12. ^ Lobpreis, T; Vrana B, Mills GA, Greenwood R (2008). "Effect of housing geometry on the performance of Chemcatcher passive sampler for the monitoring of hydrophobic organic pollutants in water". Environ Pollution 153: 706–710. http://www.sciencedirect.com/science/article/pii/S0269749107004605. 
13. ^ Aguilar-Martínez, R; Palacios-Corvillo MA, Greenwood R, Mills GA, Vrana B, Gómez-Gómez MM (2008). "Calibration and use of the Chemcatcher® passive sampler for monitoring organotin compounds in water". Anal Chim Acta 618: 157–167. http://www.sciencedirect.com/science/article/pii/S0003267008008039. 
14. ^ Aguilar-Martínez, R; Gómez-Gómez M, Greenwood M, Mills GA, Vrana B, Palacios-Corvillo MA (2009). "Application of Chemcatcher passive sampler for monitoring levels of mercury in contaminated river water". Talanta 77: 1483–1489. http://www.sciencedirect.com/science/article/pii/S0039914008006978. 
15. ^ Allan, IJ; Knutsson J, Guigues N, Mills GA, Fouillac A-M and Greenwood R (2008). "Chemcatcher® and DGT passive sampling devices for regulatory monitoring of trace metals in surface water". J Environ Monit 10: 821–829. http://pubs.rsc.org/en/content/articlelanding/2008/em/b802581a. 
16. ^ Vrana, B; Mills GA, Leonards PEG, Kotterman M, Weideborg M, Hajslova J, Kocourek V, Tomaniova M, Pulkrabova J, Suchanova M, Hajkova K, Herve S, Ahkola H and Greenwood R (2010). "Field performance of the Chemcatcher passive sampler for monitoring hydrophobic organic pollutants in surface water". J Environ Monit 12: 863–872. http://pubs.rsc.org/en/Content/ArticleLanding/2010/EM/b923073d. 
17. ^ Allan, IJ; Booij K, Paschke A, Vrana B, Mills GA and Greenwood R (2009). "Field performance of seven passive sampling devices for monitoring of hydrophobic substances". Environ Sci and Technol 43: 5383–5390. http://pubs.acs.org/doi/abs/10.1021/es900608w. 
18. ^ Greenwood R, Mills G and Vrana B, ed (2007). Passive sampling techniques in environmental monitoring (Comprehensive Analytical Chemistry series, D Barcelo (series ed.). Amsterdam: Elsevier. pp. 453. ISBN 978-0-444-52225-2. |url=http://www.elsevier.com/wps/find/bookdescription.cws_home/711413/description#description
19. ^ Vrana, B; et al. (2005). "Passive sampling techniques for monitoring of pollutants in water (Review Article)". TrAC, Trends in Analytical Chemistry 24: 845–868. http://www.sciencedirect.com/science/article/pii/S0165993605001743. 
20. ^ Allan, IJ; Vrana B, Greenwood R, Mills GA, Roig B and Gonzalez C (2006). "A "toolbox" for biological and chemical monitoring requirements for the European Union’s Water Framework Directive (Review Article)". Talanta 69: 302–322. http://www.sciencedirect.com/science/article/pii/S0039914005006636. 
21. ^ "Water quality – sampling. Part 23: Guidance on passive sampling in surface waters. ISO 5667-23:2011.". http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=50679. Retrieved 21 September 2011. 

External links

• [1] Environmental chemistry and water monitoring group, University of Portsmouth