Department Environmental Chemistry

The chlorinated and polar artificial sweetener sucralose has been registered as a food additive in the EU since 2004. It is 600 times sweeter than its parent compound Sucrose and is used in a huge variety of dietary foods. Sucralose is excreted nearly unchanged by the human body and is highly persistent in the aqueous environment.

A Swedish study from 2007 shows that sucralose is hardly degraded in the wastewater treatment plant (WWTP) and was found in concentrations up to 3.5 µg/L in the recipient waters. Due to the persistence and increasing consumption rising concentrations in natural waters can be expected for Switzerland as well. To get an overview for Switzerland the most important surface waters like river Rhine and Lake Constance were analysed. To show the infiltration behaviour of the compound a revitalised river segment and the connected groundwater were monitored. Since the WWTP is the main pathway into the aqueous environment the degradation by ozone was tested at a pilot plant. In collaboration with the Swedish university of Linköping and the Eawag department SIAM (System Analysis, Integrated Assessment and Modelling) the mass flux of sucralose from its use to its way to surface water was studied in a small Swedish catchment by combining field measurements and modelling. To analyse sucralose in the low ng/L range in different aqueous matrices an online SPE-LC-method coupled with a high resolution mass spectrometer (HRMS) was developed.