Chemcatcher is a passive sampling device for monitoring a variety of pollutants (including trace metals, polycyclic aromatic hydrocarbons, pesticides and pharmaceutical residues) in water.
Most monitoring programmes involve the periodic collection of low volume spot samples (bottle or grab) of water, which is challenging, particularly where levels fluctuate over time and when chemicals are only present at trace, yet toxicologically relevant concentrations.
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.
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 in surface waters.
The measurement of TWA concentrations can give a better indication of the long-term environmental conditions and enables improved risk assessment.