Analysis of Per- and Polyfluoroalkyl Substances in Different Media: Produce, Wastewater, and Air

Per- and polyfluoroalkyl substances (PFASs) occur in a wide range of media. As a result, human exposure can occur via different routes, including inhalation and ingestion of drinking water and food.

This presentation will summarize analytical methods developed in our laboratory at NC State University to determine PFAS concentrations in (1) produce grown in backyard gardens in the vicinity of a fluorochemical manufacturing plant, (2) wastewater, and (3) air in the vicinity of aeration basins of wastewater treatment plants.

The analytical method for produce closely follows EPA Method 1633 but was modified to enhance the recovery of short-chain PFASs, including short-chain per- and polyfluoroalkyl ether acids (PFEAs). This method targets 45 PFASs, including 13 PFEAs, and its application showed that short-chain PFEAs occur at concentrations of up to 38 ng/g as-received weight in water-rich produce grown in the vicinity of a fluorochemical manufacturing plant. For the analysis of wastewater and air, gas-chromatography-tandem mass spectrometry (GC-MS/MS) methods were developed to complement liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Compounds amenable to GC-MS/MS analysis [primarily 6:2 fluorotelomer alcohol (6:2 FTOH)] represented a substantial fraction of the summed PFAS concentrations in both wastewater and air sampled proximal to aeration basins. Although the fraction of PFASs transferred from wastewater to air was small, PFAS concentrations in air suggest that inhalation exposure to aerosolized and volatilized PFASs can be important for workers in wastewater treatment plants.

Presenter: Detlef Knappe (Dept. of Civil, Construction, and Environmental Engineering, NC State University)

Detlef Knappe is the S. James Ellen Distinguished Professor of Civil, Construction, and Environmental Engineering at NC State University. He received his BS, MS, and PhD degrees from the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign, and he joined the NC State faculty in 1996. He is the Deputy Director of NC State’s Superfund Center “Environmental and Health Effects of PFAS” and is a member of NC State’s Center for Human Health and the Environment. Detlef’s research interests broadly encompass drinking water quality and treatment. He is a member of the North Carolina Secretaries’ Science Advisory Board and serves as Associate Editor for AWWA Water Science.