Why Choose Chemcatcher®

Chemcatcher® is a passive sampling device, capable of monitoring ultra-trace micropollutants in surface water, groundwater and coastal water monitoring applications. It has many advantages compared with traditional grab or spot sampling, biota, and, indeed, other forms of passive sampling.

  • Chemcatcher®  a low-cost and passive (non-mechanical) device, with no power, maintenance or supervision requirements.
  • Different combinations of the membrane and receiving phase allow Chemcatcher® to be tailored for different purposes.
  • This enables screening for the vast majority of problematic aquatic micro-pollutants, including both polar and non-polar organic compounds such as PAHs, PCBs, PBDEs, pharmaceuticals, pesticides, as well as radionuclides, trace metals, metalloids and organometallic compounds.
  • The device can be deployed in situ for varying durations – typically from a minimum of 7 days to an average of a month.
  • This allows the target compound to be sequestered continually from the environment. Thus, Chemcatcher® captures sporadic, transient inputs of pollutants and fluctuations in levels over time, and a time-weighted average can be calculated for the deployment period.
  • In some cases, the amount of chemical accumulated by the device reflects the freely dissolved and labile fraction that is most readily bioavailable, thus providing a more accurate indication of impact on the ecosystem.

Advantages compared with grab or spot sampling

  • The conventional approach to water quality monitoring – collecting samples in bottles and bringing them back to the laboratory for analysis – can be expensive and time consuming. Likewise, automated samplers can be expensive, vulnerable to theft or vandalism, and require maintenance, and, again, laboratory analysis costs can be significant.
  • Spot sampling simply reveals the level of pollution at the particular time of sampling. In real-life aquatic environments, concentrations can vary over time, due to sporadic effluent discharges, tidal impacts, rainfall variations and so on.
  • For some priority substances, environmental quality standards (EQS) demand detection at extremely low levels, particularly in marine environments. When contaminants are present at such low levels, it may be necessary to collect large volumes of water and concentrate the sample prior to analysis to reach detectable levels.

Advantages compared with biota

  • Certain substances, targeted for monitoring under environmental legislation, bioaccumulate in protein-rich tissue within aquatic species, such as fish, allowing biota monitoring to be used to detect environmentally relevant concentrations of lipophilic substances, and, as bioaccumulation represents exposure over time, this can provide a time-weighted representation.
  • However, in practice, there are a number of difficulties associated with biota monitoring. For instance, there can be challenges finding the correct species, size range, age, etc at a given location. In extreme cases, poor water quality conditions may make it impossible for the targeted species to survive. Furthermore, issues such as metabolism and intraspecies biological variability can further cloud the comparability of results.
  • In contrast, with Chemcather® the results are site specific; samples are easier to extract and potential problems associated with metabolism are eliminated.

Benefits compared with other passive device

  •  Chemcather® can detect both polar and non-polar compounds, extending its applications.
  • Because it uses a disk as opposed to beads, there is increased absorption across the whole of the disk.
  • The larger surface area provides improved performance for the detection of phramceuticals and pesticides.
  • The Chemcather®  casing is re-usable, allowing the user to move away from single-use plastic and providing better value for money in cases where multiple deployments will be required.