Details

Autor(en) / Beteiligte

• Jin, Yukun

Titel

Development of a Low-Cost Solid-Phase Extraction Method for the Rapid Measurement of PFAS in Environmental Waters

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2024

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• A large class of synthetic compounds known as per- and polyfluoroalkyl substances (PFAS) has become ubiquitous in the environment due to their widespread use and extreme persistence. While providing convenience in various applications, they pose a threat to the environment and to living organisms. The risk of human exposure to PFAS and the associated health effects have gained considerable attention in recent years. Contaminated water consumption has emerged as one of the major pathways for human exposure, and studies have identified elevated PFAS concentrations in human blood linked to polluted drinking water sources. In response to the escalating concern surrounding PFAS, the U.S. Environmental Protection Agency has proposed new maximum contaminant levels for six PFAS, notably setting stringent limits of 4 ppt each for PFOA and PFOS. This regulatory advancement, while crucial for public health, introduces challenges in the routine and regular monitoring and detection of PFAS in water samples.Despite the development of various methods for total fluorine measurement and targeted PFAS analysis, those techniques often fall short in achieving the low ppt level required for efficient PFAS measurement or are time-consuming and expensive. As an innovative alternative, particle-induced gamma-ray emission (PIGE) spectroscopy has been developed and employed as a rapid, sensitive, and cost-effective method for screening total adsorbable organic fluorine (AOF) in water samples. The PIGE analysis is integrated with a solid-phase extraction (SPE) method utilizing commercially available and low-cost graphite activated carbon fiber (GACF) felt to pre-concentrate and extract PFAS from water samples before analysis. To accommodate diverse water sample types, including drinking water, groundwater, and surface water, the method has been further developed to address various challenges. Specifically, a methanol rinse method distinguishes inorganic fluoride and organic fluorine from PIGE analysis, an acid rinse method differentiates inorganic fluoride and ultrashort-chain PFAS from longer-chain PFAS, and Fenton’s reagent is employed to eliminate dissolved organic carbon content, which prevents reduced AOF signals from PFAS in PGE analysis.Chapter 1 provides an introduction to PFAS, explores related PFAS studies in water samples, reviews current methods for measuring PFAS, and highlights the use of PIGE as a rapid screening technique. Chapters 2 details the methodology involving SPE, PIGE, methanol rinse, and acid rinse, outlining a comprehensive workflow for real-world water sample collection. Chapters 3 to 5 delve into the application of the developed method in different types of water samples, including drinking water samples from northern Indiana, surface water, and groundwater samples from Orange County, California, and surface water samples from the northern Indiana coastal region. Results from these studies, along with preliminary findings on ultrashort-chain PFAS, are presented. Chapter 6 consolidates the findings from each study and outlines the achievements and future plans for Forever Analytical Services, a startup company that is using this method. The PIGE method of screening for total AOF as a surrogate for PFAS has been demonstrated to be a reliable, rapid, and cost-effective technique in real-world water samples and is suitable for routine PFAS monitoring.