Non-Target- and Target-Analysis of Per- und Polyfluoralkyl Substances (PFASs) and Their Transformation Products in Contaminated Environmental Samples
Per- and polyfluoroalkyl substances (PFASs) are industrially produced chemicals broadly used in consumer products, in fire-fighting foams and as coating materials, exemplarily for cookware, textiles and paper packaging. The Organization for Economic Co-Operation and Development (OECD) so far lists ca. 4700 technical PFASs with a variety of molecular structures and functional groups, resulting in different physical and chemical properties, responsible for a complex behavior of degradation and transfer potential of the multitude of PFASs potentially present in the environment. Of highest concern are the vastly studied terminal transformation products perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), due to their industrial significance, environmental persistence, bioaccumulative character and toxicological effects.
In 2013, high levels of PFAS degradation products, inter alia PFOA, were detected in a drinking water well near Rastatt in Baden-Württemberg, Germany. The contamination source was found to be most likely PFAS-coated paper sludge-amended compost, which was brought onto more than 1000 ha of agricultural fields around Rastatt and Mannheim during the 2000s. This contamination case is closely studied in the FluorTECH project, funded by the Ministry of the Environment, Climate Protection and the Energy Sector Baden-Württemberg.
An important objective is to investigate the transformation and transfer of PFASs from technical products in soil, crops and drainage water. By means of comparison of analytical results of technical PFAS products in soil column, crop growth and degradation experiments, and from samples taken from the contaminated areas, the technical products involved in the contamination are to be identified and their PFAS constituents quantified.
Within work packages located at the Analytical Chemistry Department at the UFZ, ultra-high resolution mass spectrometric techniques (by implementation of Fourier Transformation-Ion Cyclotron Resonance Mass Spectrometry, FT-ICR MS) will be used in a novel non-target approach for the detection of unknown PFASs. Ultra-High Performance Liquid Chromatography Tandem-Mass Spectrometry (UHPLC-MS/MS) will furthermore be applied for the development of targeted quantitative multi-methods for ionic and neutral PFASs.
The overall aim of the FluorTECH project is to close the mass balance of organofluorine in contaminated soils, plants and groundwater at the contamination site and to forecast the future environmental behavior of the PFASs present in the fields. Finally, this study aims to improve the understanding of the environmental fate and risk assessment of PFASs and their precursors.