Short-term pollutant peak concentrations severely underestimated
The mobile and automated MS2field mass spectrometer allows for on-site measurements of harmful substances in surface waters with high temporal resolution. The initial measurements using the device are reveal the extent to which peak concentrations of pesticides, for example, have been underestimated by traditional methods so far.
Acutely toxic peak concentrations
MS2field automatically collects, prepares and analyses a sample every 20 minutes, allowing major changes in concentration – by several orders of magnitude in the space of hours or days – to be detected with unprecedented clarity. Over the same measurement period, the researchers also collected conventional composite samples – each of them over a period of 3.5 days – which they analysed in the laboratory in the traditional way.In doing so, the team was able to demonstrate the extent to which the traditional method underestimates peak concentrations because they are missed, or rather diluted.
Taking the insecticide thiacloprid as an example, the work also revealed the importance of short-term peak concentrations from an ecotoxicological perspective. Indeed, the quality criterion enshrined in the Swiss Water Protection Ordinance with a view to preventing acute damage to aquatic organisms was exceeded on several occasions and many times over (by a factor of up to 30). For many pesticides, the peak concentrations recorded in the 20-minutely MS2field measurements exceeded the average concentrations recorded in the 3.5-day composite samples by a factor of up to 170.
Reference publication
Anne Dax, Michael Stravs, Christian Stamm, Christoph Ort, Daniele La Cecilia, Heinz Singer (Eawag)
Mikroverunreinigungen mobil messen mit MS2field
Aqua&Gas 12/2020
pdf in German available at eawag news link below
Source
Admin.ch News
EAWAG News