Tracking PFAS in Drinking Water: A Review of Analytical Methods and Worldwide Occurrence Trends in Tap Water and Bottled Water

Per- and polyfluoroalkyl substances (PFAS) used in various industrial applications are pollutants of concern for the environment and human health. Drinking water consumption is one key exposure pathway to PFAS, as recently highlighted by multiple studies on their occurrence in tap and bottled water worldwide. However, PFAS quantification at low part-pertrillion (ng/L) or part-per-quadrillion (pg/L) concentrations remains challenging. PFAS presence in blanks and incomplete method recoveries can lead to false positives or negatives; PFAS concentration changes under different storage durations or conditions can also affect accuracy and precision. Here, we review the most recent data related to analytical methods that were used in research articles for the detection and quantification of PFAS from drinking water. Commonly encountered pitfalls are summarized, and analytical performance is appraised including detection limits, recovery, matrix effects, and other quality assurance/quality control endpoints. In addition, we collated available guidelines for health advisory levels of PFAS in tap water. Finally, we compiled concentration data on legacy and emerging PFAS in tap and bottled water.