Per- and polyfluoroalkyl substances (PFAS) are synthetic fluorinated compounds that havebeen detected in wildlife, humans and in the environment. They have C-F bonds thatcontribute to their thermal stability which make them extremely resistant to degradationunder environmental conditions. The most commonly studied classes of PFASs areperfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs), of whichperfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are the two mostfrequently measured and detected compounds in biota.In this study, an extraction method using protein precipitation extraction (PPT) wasdeveloped and its performance in terms of procedural blank, recovery and amount of PFASbeing extracted was compared to those of the ion pair extraction (IPE) for the analysis ofPFASs and EOF in both serum and whole blood samples. The results showed low recoveryfor PPT extraction with ACN using two extraction cycles, the average recovery rangedbetween 60% and 125%. However, the recovery for some compounds was below 50%.Therefore, one extra extraction cycle was added, enhancing the recovery by 24% and theresults were then comparable to IPE where the recovery ranged between 90% and 120%.Combustion ion chromatography (CIC) was used to compare the levels of extractableorganic fluorine (EOF) for both methods. However, the EOF analysis could not beperformed due to issues caused by the matrices present after PPT which resulted indamage of the combustion tube as well as interfering peaks that affected the analysis offluoride.