The presence of per- and polyfluoroalkyl substances (PFAS) in surface water, groundwater, and finished drinking water is receiving increased attention due to the toxicity and carcinogenicity of these compounds. While low toxicity thresholds of these compounds and the evolving regulations require sensitive analytical techniques capable of detecting PFAS concentrations in sub-ng/L levels, the ubiquitous presence of PFAS in lab supplies and instrument parts makes it crucial to prepare samples with minimize contamination. Meanwhile, as the fluorochemical manufacturers shift their products from legacy PFAS to alternative species, more emerging PFAS species have been identified in recent years. Routine PFAS quantification has been relying on liquid chromatography–mass spectrometry (LC/MS). Although LC/MS has been a useful tool for analyzing legacy PFAS, it is limited by the availability of the analytical standards or even structural information of the emerging PFAS species. As a result, nontargeted analysis using high-resolution mass spectrometry as well as different techniques for total PFAS analysis has been developed. With these tools, significant efforts have been made to identify and quantify infrequently reported PFAS species, and as a result, the occurrence of many novel species has been revealed. For example, per- and polyfluoroalkyl ether acids (PFEA) are a family of emerging PFAS that are discharged to the environmental as replacement products made by the fluorochemical manufacturers and as industrial byproducts. An important species in the PFEA family, the ammonium salt of hexafluoropropylene oxide dimer acid (with the trade name of “GenX”), has have been detected in waterbodies in multiple countries. The occurrence of GenX and other structurally related PFEA species in North Carolina is discussed as a case study to demonstrate how the analytical advances promoted the awareness and removal of these compounds from the environment.