The developed effect-based analysis of micropollutants enables the sensitive and robust detection of previously unknown pollutants in environmental samples by a direct coupling of thin-layer chromatography and biological assays.

With currently more than 350,000 substances, the number of industrially produced chemicals has more than tripled in the last 20 years. In Europe, water-bodies are monitored for a limited list of selected substances that pose a risk for humans and the environment. In addition to these regulated substances, however, many other pollutants may be present in the aquatic environment, some of which are unknown and thus cannot be captured by list-targeted chemical analysis. The advantage of the developed effect-based method is that the presence of problematic substances can be detected based on their undesired biological effects. Samples, which often contain a cocktail of known and unknown substances, are separated using thin layer chromatography. After the separation, the surface of the thin-layer plate is examined directly by using various biological test methods to detect genotoxic, dioxin-like, phytotoxic or various hormonal effects. For example, the contraceptive 17a-ethinylestradiol can be detected in the lower pg/l range in environmental samples by this method. If the test is positive, i.e. if undesired effects are detectable, bio-active chemicals causing respective effects are present in the investigated sample. Based on the various tests, activity profiles are generated for individual samples. These profiles allow to specifically identify the triggering compound class - even if it is not yet known or regulated. The developed method can be applied to identify sources of pollutants, as well as to assess the efficiency of technical processes, e.g. the efficiency of wastewater treatment.

The tool was developed within the German-Israeli water technology cooperation project :"Tracking effects of environmental organic micro-pollutants in the subsurface" (TREES) 02WIL1387