Because of the very low levels at which PFAS are found in real samples (typical concentration values are sub- to low-nanograms per liter), analyte enrichment through solid phase extraction(SPE) or liquid liquid extraction (LLE) is required before analysis[5,12,14–18]. Moreover, clean-up of crude extracts is essential for destruction and removal of lipids and other co-extractives that may interfere in the instrumental determination. As variable recoveries are often obtained for these compounds, another caution that should be taken is to use isotopic internal standards (ISs) [5,13,15].Due to the general large consumption of milk of the worldwide population, especially children, as well as its use in other products such as prepared foods and baby formula, milk could be a large contributing factor to the overall dietary human exposure to PFAS.