Restricted Research - Award List, Note/Discussion Page
Fiscal Year: 2023
1549 The University of Texas at Arlington (143437)
Principal Investigator: Charles p Shelor,shelor@uta.edu,(817) 272-0442
Total Amount of Contract, Award, or Gift (Annual before 2011): $ 298,143
Exceeds $250,000 (Is it flagged?): Yes
Start and End Dates: 9/15/22 - 8/31/25
Restricted Research: YES
Academic Discipline: Department of Chemistry and Biochemistry
Department, Center, School, or Institute: none
Title of Contract, Award, or Gift: Portable Absorbable Organic Fluorine Analysis for Poly- and Perfluoralkyl substance guided sampling
Name of Granting or Contracting Agency/Entity:
National Science Foundation (NSF)
CFDA Link: NSF
47.049
Program Title:
Chemical Measurement and Imaging (CMI)
CFDA Linked: Mathematical and Physical Sciences
Note:
(SAM Category 1.1.1.)Poly- and perfluoroalkyl substances (PFAS) are a class of persistent anthropogenic chemicals first developed in the 1950’s. The high stability and surface activity of PFAS led to routine use in household products including electronics, nonstick cookware coatings, upholstery protectors and electronics as well as in aqueous film-forming-fire-fight foams. Frequently, PFAS are referred to as forever chemicals due to their environmental persistence. The prolific use across industries means that PFAS have been measured in even the remotest regions of the globe. PFAS bioaccumulate and lead to a variety of health conditions including endocrine disruption, ulcerative colitis, diabetes, and cancer among others. As such, national health advisory levels for drinking water are at a remarkable 70 part per trillion combined for perfluorooctanoate and perfluorooctane sulfonate. Measurement of PFAS is challenging and typically performed by liquid chromatography (LC) coupled to tandem mass spectrometry (MS) after large volume sample preconcentration. The ubiquity of PFAS however requires extraordinary care to avoid contamination as well as prevent losses due to sorption to the sampling handling containers. PFAS are also a broad class with hundreds of identified chemicals and production of alternative next-gen substitutes requires the method to be updated, further increasing the complexity and cost. Alternatively, mineralization of PFAS and measurement of the produced fluoride as is done in combustion ion chromatography may be used as a total PFAS measurement to justify subsequent LC-MS/MS analysis.Intellectual Merit: To reduce the number of samples necessary for LC-MS and avoid sample contamination due to handling, a field portable instrument capable of measuring total absorbable fluorine is proposed. Briefly, sample PFAS will be adsorbed on functionalized filter media, undergo mineralization in a cold plasma discharge, and be measured by capillary ion chromatography. Mineralization of PFAS in a traditional combustion furnace is too energy intensive to be field portable and instead will be performed by a dielectric barrier discharge (DBD). The DBD is a cold plasma that generates ozone, radical species as well as UV light, providing an energy efficient means to break down PFAS. The plasma will be focused onto the surface of glass, quartz, or silver membrane filters that withstand plasma treatment. The filters will be functionalized to sorb PFAS from the sample while allowing inorganic fluoride to be removed. The digest will then be preconcentrated on zirconia based stationary phases highly selective for fluoride prior to separation by capillary ion chromatography (IC). Capillary IC will be performed using packed columns and commercial components or in an open tubular format; the latter permits approximately 100 times greater concentration factors. Limits of detection are anticipated to be in the low parts per trillion for adsorbed fluoride, even if combined sorption and mineralization recovery is low. The instrument will be used to measure public surface waters including a local area of known PFAS contamination. Broader Impacts: PFAS are unequally distributed. Most heavily affected areas are in industrial centers, landfills, airports and military bases where the surrounding community is typically economically disadvantaged. The high cost of LC-MS analysis makes characterizing every water supply, particularly in rural less affluent communities difficult.
Discussion: No discussion notes