Chemcatcher

Capabilities

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:

Petersfield_outlet_Janine Non-polar organics version – 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.

Polar organics version - 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®.

Metals version - 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.

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