Starting from testing individual PFAS substances to real, complex PFAS-contaminated water samples

As part of PROMISCES, the German Environment Agency (UBA) has co-developed a suitable test battery that is animal-free and cell-based. With it, 44 individual PFAS substances were tested. The TTR-TR CALUX showed the best results of all biotests used in the test battery. It indicates an inhibiting effect on the binding of a thyroid hormone (T4) to the corresponding transport protein transthyretin (TTR) in almost 80 % of the examined PFAS.

These laboratory results were then tested in practice over the last months. In case study 1, both groundwater samples contaminated with PFAS and water samples from various purification stages were examined. To carry out the procedure, the water samples had to be concentrated using a solid phase extraction (WAX-SPE). The method for this was also developed in PROMISCES. The results show that the influent samples have an increased activity in the CALUX test, while the water samples from the treatment steps have a lower activity or are below the Limit of Quantification. . The blanks (deionized water) are negative and the positive controls (PFOA) show corresponding effects.

Our test results show that the test battery developed in PROMISCES can detect the presence of a large number of PFAS, even in complex real water samples.primarily via the effects in the TTR-TR CALUX.