Identification of polar bioactive substances in the Upper Rhine using effect-directed analysis

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Persistent, Mobile and Toxic (PMT) and very persistent and very mobile (vPvM) substances pose significant environmental risks.
• Identifying and evaluating these substances in complex environmental matrices like water is challenging.
• Effective methods are needed for prioritizing chemicals for risk assessment and regulation.

Purpose of the Study:

• To apply Effect-Directed Analysis (EDA) for identifying bioactive compounds in surface and well water from the Upper Rhine.
• To evaluate identified compounds against criteria for PMT and vPvM substances.
• To demonstrate the effectiveness of EDA in prioritizing chemicals for environmental risk assessment.

Main Methods:

• Multi-layered solid-phase extraction for enrichment of polar substances.
• Fractionation of extracts and testing using transthyretin (TTR)-binding and Aliivibrio fischeri bioluminescence (AFB) bioassays.
• High-resolution mass spectrometry guided by bioassay results and suspect lists for chemical identification.

Main Results:

• Ten bioactive substances were identified and confirmed.
• Four substances (diclofenac, trifloxystrobin acid, 6:2 FTSA, PFOA) were evaluated as PMT and vPvM.
• One substance (4-aminoazobenzene) was identified as a potential PMT substance.

Conclusions:

• Effect-Directed Analysis (EDA) is effective for identifying PMT/vPvM substances in aquatic environments.
• EDA facilitates the prioritization of chemicals for comprehensive environmental risk assessment.
• The study highlights key PMT/vPvM contaminants in the Upper Rhine water samples.