PFAS - Leaching Tests
A big difference between PFAS and several others organic environmental pollutants is that many of PFAS substances have a relatively high water solubility, which applies especially to perfluorinated sulfonates and acids (PFSA/PFCA). At the same time the strength of adsorption onto environmental solids such as soil may be limited in comparison to more hydrophobic organics such as PAH, PCB, chloro-pesticides etc. Studies performed by Eurofins show that up to 80% of C4-C6 PFAS can be leached from soil in a L/S=10 batch test.
Eurofins has worked with PFAS leaching tests for several years and has, for example, tested the PE plastic containers and other equipment used for our batch tests. This also includes 0.45 µm filters in cases where it is intended to filter the leachate. Three options for leachate treatment have been developed: (1) sedimentation and decantation, (2) sedimentation and centrifugation, and (3) 0.45 µm filtration. The standard for batch tests (EN12457) does not provide guidance regarding pretreatment, but e.g. in EN14405 (column test) centrifugation is specified. Results from our tests show that when filtering, a good yield is obtained for PFAS with a chain length up to C10-C12 (depending on structure), e.g. SLV PFAS11 works satisfactorily. Generally, packages for PFAS in "unclean" water are used for leachate and there is also the possibility to analyze TOP (total oxidizable precursors).
As guidance before ordering, we have produced a product flyer that describes our leaching tests with regard to PFAS as well as a special order form where different batch tests, pre-treatments and analytical packages can be selected. Delivery time is normally 15 working days. For questions about column tests or trials with stabilizing additives, contact us.