Perfluorooctanoic acid (PFOA) belongs to a class of perfluorinated contaminants (PFCs), a class of organic contaminants, which are widely used in everyday products, such as paints, adhesives, textiles, waxes, and in non-stick coatings in kitchen utensils. Because of its chemical properties, PFOA is very stable, does not degrade naturally and bioaccumulates in the food chain. It has been classified as a highly persistent pollutant. Analysis of PFOA in environmental matrices is challenging because the trace detection is required in conditions of possible instrumental contamination. The parts of standard HPLC systems contain fluoropolymers that may pose the leach of PFOA into the mobile phase, creating false positives and high blank levels. NOTE: The presented analytical method is designed to resolve background contamination of long chain PFAS. The separation efficiency was tested only with the presented combination of analytical and delay HPLC columns.