Monitoring aquatic pollution
Most environmental monitoring programmes involve the periodic collection of low volume spot (bottle or grab) samples of water. This is challenging, particularly where concentrations fluctuate over time and where chemicals are only present at trace levels. The Chemcatcher® can be used to solve this problem.
The Chemcatcher® technology has been developed over the last 20 years and has been used by academic scientists, governmental and environmental agencies and the water industry throughout the world.
An easy to use and cost effective device, it can be used to monitor a wide range of pollutant classes covering most applications required in the aquatic environment.
Chemcatcher® is patented and a registered trademark in Great Britain and Northern Ireland.
What is Chemcatcher?
The original design concept of the Chemcatcher® was to develop an easy to use sampler for monitoring a range of pollutant classes by altering the combination of commercially available receiving phase and diffusion limiting membrane used. The use of quality controlled, commercially available solid receiving phases allows high reproducibility as compared to other hand-made passive sampler devices.
Chemcatcher® comprises a robust, reusable three-component a low-cost, three component, water-tight PTFE body. Two different designs are available to accommodate different types of commercially available 47 mm diameter receiving phase disks:
3M EmporeTM Chemcatcher®
Weighs 83 g and houses the 47 mm 3M EmporeTM range of receiving phases (e.g. C18, SDB, chelating, anion and cation exchange and RAD disks). As well as the appropriate EmporeTM receiving disk, a diffusion-limiting membrane is also required.
Horizon AtlanticTM Chemcatcher®
Weighs 130 g and houses the 47 mm Horizon AtlanticTM SPE disks as receiving phases (e.g. HLB, C18 and DVB). As well as the appropriate AtlanticTM receiving disk, a diffusion-limiting membrane is also required.
Capabilities and modes
The Chemcatcher® comprises a small three component PTFE body into which a 47 mm 3M Empore™ disk is inserted as the receiving phase. This is selected according to the class (e.g., non-polar organic, polar organic, metals, radionuclides) of compounds being measured. In some applications a thin diffusion limiting membrane is placed over the receiving phase so as restrict the rate of uptake of pollutants. Three different versions of the Chemcatcher® are available commercially and these different designs cover most of the monitoring applications that are required in the aquatic environment.
Different combinations of receiving phase disks and overlaying diffusion limiting membrane are used for monitoring the three broad classes of pollutants frequently found in the aquatic environment.
This uses a C18 Empore™ disk receiving phase that can be overlaid with a low-density polyethylene (LDPE) diffusion limiting membrane as required. The interstitial gap between the receiving phase and membrane is filled with a small quantity of n-octanol to increase the rate of uptake of pollutants. Performance reference compounds (PRCs) can be used with this version of the Chemcatcher® to provide in situ calibrations.
This uses either an SDB-RPS or SDB-XC Empore™ disk receiving phase that can be overlaid with a thin polyethersulphone diffusion limiting membrane as required. Performance reference compounds (PRCs) cannot be used with this version of the Chemcatcher®.
This uses a chelating Empore™ disk receiving phase that can be overlaid with a cellulose acetate diffusion limiting membrane as required. Performance reference compounds (PRCs) cannot be used with this version of the Chemcatcher®.
Other versions of the Chemcatcher® have been developed for monitoring radionuclides and organo-metallic compounds.
Monitor a wide range of pollutants
Chemcatcher® can be used to monitor:
- Trace metals
- Organo-metallics (TBT)
- Polar organics (including metaldehyde)
- Non-polar organics
Chemcatcher® is a passive sampling device developed by researchers at the University of Portsmouth, Portsmouth, UK and Chalmers University of Technology, Göteborg, Sweden.
These cost-effective devices are used alongside, or can replace, established water monitoring approaches that rely on infrequent spot or bottle sampling.
The Chemcatcher® comprises a three-component PTFE body. Two principal designs are currently available for housing two different types of 47 mm diameter receiving phase.
All of the samplers use commercially available (manufactured by 3M or Horizon) receiving phases bound (in either a PTFE or glass fibre matrix) into 47 mm disks. These can be purchased from a number of international suppliers. These disks are produced in a wide range of chemistries, being quality assured by the manufacturer and are directly compatible with conventional laboratory sample extraction apparatus. The use of a bound receiving phase ensures that the active sampling area of the device remains constant during laboratory calibration uptake experiments and in field deployments. This increases reproducibility of the measurements
The team recognises that in some cases, detailed information may be required before the next steps are taken to use Chemcatcher®. Should you require help or advice, you can contact the team using the contact details below:
Chemcatcher®, Office 0.32 Burnaby Building, University of Portsmouth, Winston Churchill Avenue, PO1 2UP, Portsmouth, UK
Tel: +44(0)23 9284 2292
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