Assessment of Suspected and Unknown Anthropogenic Trace Contaminants in Aquatic Systems (STOFF IDENT)

Classical wastewater treatment processes are sometimes ineffective for the removal of pharmaceuticals, which can reach the aquatic environment. Their presence and fate in water bodies are receiving growing interest, since pharmaceuticals have been identified as a class of new emerging environmental contaminants. Recently, advanced oxidation processes (AOPs) have come into focus as effective and environmentally friendly technologies to degrade persistent pollutants. At the same time, the study of their transformation products (TPs) is considered of primary importance, as they may represent a risk even higher than the parent compounds. TPs produced by AOPs are in general smaller and more polar than the parent drugs, and in most cases reference standards are not available. In this context, versatile and reliable analytical tools for the simultaneous screening of pharmaceuticals and their suspected and unknown TPs in a wide range of polarity are still missing.

Hydrophilic interaction liquid chromatography (HILIC) is a technique for the separation of hydrophilic molecules, whereas reversed-phase liquid chromatography (RPLC) is ideal for the retention of more hydrophobic compounds. We have recently developed a serial coupling of RPLC and HILIC with high accurate mass spectrometric detection (Time of Flight Mass Spectrometry) for the analysis of complex mixture. This technique has been, thereafter, successfully applied for monitoring the fate of pharmaceuticals, such as diclofenac and sulfamethoxazole, in wastewater during AOP treatments. At the same time several polar and apolar suspected TPs have been identified on the basis of their chromatographic behavior and mass data.

Further experiments will be directed to the use of RPLC/HILIC coupling with tandem mass spectrometry for the identification of unknown TPs. All the potential and identified anthropogenic trace contaminants will be collected in database (“STOFF-IDENT”) to be provided to the expert audience.