Screening for Per- and Polyfluoroalkyl Substances in Water with Particle Induced Gamma-Ray Emission Spectroscopy

Abstract

A new method for rapidly screening drinking water for the presence of per- and polyfluoroalkyl substances (PFAS) has been developed. This method involves gravity filtering drinking water through an activated carbon felt and subsequently analyzing the surface of the felt with particle induced gamma-ray emission (PIGE) spectroscopy. Using this technique, the total fluorine measurements by PIGE produced linear calibration curves adequate to measure below 50 ppt total fluorine from PFAS in drinking water for as little as 2 L of sample. Inorganic fluoride and PFAS were successfully differentiated by acidifying the sample prior to filtration. Acidification did not affect the anionic PFAS binding to the activated carbon filter, while the inorganic fluoride did not bind to the filter below pH 2. This method is quantitative when measuring individual PFAS; however, as a total fluorine measurement, PIGE cannot differentiate between individual PFAS in a mixed solution. Since most environmental or drinking water samples will likely contain a mixture of PFAS, this method could be used as a preliminary screening tool to identify samples with elevated total extractable organo-fluorine from anionic PFAS that can be analyzed by compound-specific methods subsequently to quantify individual analytes.

Water Analysis: Emerging Contaminants and Current Issues

“…Tighe et al developed a new particle-induced gamma-ray emission (PIGE) spectroscopy method to screen for PFAS in drinking water . This total fluorine method could achieve 50 ng/L LODs with a 2 L sample.…”

“…Tighe et al developed a new particle-induced gamma-ray emission (PIGE) spectroscopy method to screen for PFAS in drinking water. 59 This total fluorine method could achieve 50 ng/L LODs with a 2 L sample. Inorganic fluoride and PFAS could be differentiated by acidifying the sample prior to filtration, preventing inorganic fluoride from binding to the activated carbon filter.…”

Sources, Fate, and Detection of Dust-Associated Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS): A Review

“…These instruments are capable of measuring both known and unknown analytes, and data can be stored in HRMS for analyzing new analytes later. Some of the new detection methods recently developed used particle-induced gamma ray emission spectroscopy (PIGE) [93,94] and fluorine nuclear magnetic resonance (19F-NMR) [95]. The limit of detection (LOD), the limit of quantification (LOQ), the method detection limit (MDL), and the method quantification limit (MQL) varied among samples from water, soil, and air/dust, as shown in Table 3.…”

Analysis of needs for enforcement of PFAS in articles and chemical products

“…As PIGE requires solid samples for analysis, to analyse water samples, a solid-phase extraction method for collecting the PFAS from drinking water is necessary. PIGE has been applied by Tighe et al (2021) to a rapid screening of drinking water for the presence of PFAS. The method used makes use of iltering the drinking water over an activated carbon felt by use of gravity forces.…”