A sensitive method for the detection of legacy and emerging per- and polyfluorinated alkyl substances (PFAS) in dairy milk

Abstract

There is widespread contamination by per-and polyfluoroalkyl substances (PFAS) across the globe, with adverse effects on human and environmental health. For human exposure, drinking water and dietary exposure have been recognized as important PFAS exposure pathway for the general population. Several documented cases of dairy milk contamination by PFAS have raised concerns over this exposure pathway in general. A sensitive method for determination of 27 PFAS in milk was hence modified and applied on raw and processed milk samples from 13 farms across the United States (U.S.). A combination of acid and basic extraction method and ENVI-Carb clean-up achieved recoveries of targeted PFAS between 70 and 141%. The method detection limits (MDL) ranged from 0.8 to 22 ng/L (for 26 PFAS) and 144 ng/L for perfluorobutanoic acid (PFBA). The uniqueness of this method is considered in the targeted screening of a broad range of legacy PFAS, as well as perfluorinated sulfonamide species and fluorotelomer sulfonates. No legacy PFAS were detected in 13 milk samples from regions of concern given local use of biosolids or proximity to fire training areas. Overall, then, the uptake of perfluoroalkyl acids (PFAA) from dairy milk in the U.S. is considered low.

Separation of perfluoroalkyl substances by ion chromatography with a resorcinarene stationary phase

“…PFAS can be detected in the ppb range [11][12][13][14][15]. Thus, IC can be used to analyze PFAS in the ppm range and techniques like LC-MS/MS should be used for very low concentrations of PFAS.…”

“…PFAS do not readily decompose and persist in the environment for years. They have Environmental Protection Agency has published detection guidelines [9][10][11][12][13][14][15]. These methods require advanced instruments, such as LC-MS/MS, and often involve complicated steps, like pouring a large amount of sample into an SPE cartridge and then extracting the analytes by methanol, followed by concentration.…”

Binding of Per- and Polyfluoroalkyl Substances to β-Lactoglobulin from Bovine Milk

“…Compared to the other PFSAs, SC8 had the lowest K d of 22.7 ± 1.8 μM for β-LGA and 23.2 ± 0.9 μM for β-LGB (Table 1). Given that the concentration of β-LG in dairy milk is ∼3 mg/mL (∼160 μM) and PFAS are typically detected at sub-ppb levels in dairy milk, 63 the measured K d values (Tables 1 and 2) indicate that if any of the PFCAs C8 to C13, the PFSA SC8, and the PFOSA SA8 are present in dairy milk, these ligands will be nearly completely bound to β-LG (and/or other proteins and lipids) assuming the binding site is unoccupied.…”

PFASs in Soil: How They Threaten Human Health through Multiple Pathways and Whether They Are Receiving Adequate Concern

“…Some common animal products in the supermarket, such as dairy milk, infant formula, and meat, ,, have also been detected with PFASs. Dairy milk contains various PFASs due to the binding of PFASs to β-lactoglobulin proteins in cow milk. , Concentrations of PFASs in milk are generally lower (Table ). However, due to high intake and the new much lower TWI value, dairy products also increase human, especially children, PFAS exposure risk .…”