Grantee Research Project Results
Final Report: Rapid Field Trace Detection of Perfluoroalkyl Substance in Water
EPA Contract Number: 68HERC20C0052Title: Rapid Field Trace Detection of Perfluoroalkyl Substance in Water
Investigators: Wang, Qingwu
Small Business: 2WiTech, LLC
EPA Contact: Richards, April
Phase: II
Project Period: June 1, 2020 through May 31, 2022 (Extended to November 30, 2022)
RFA: Small Business Innovation Research (SBIR) - Phase II (2020) Recipients Lists
Research Category: Small Business Innovation Research (SBIR)
Description:
Due to increasing concerns over the long-term health effects of PFAS on the human body, regulatory agencies have set limits for the concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS) in drinking water. In 2016, the United States Environmental Protection Agency (USEPA) established a lifetime health advisory (LHA) level of 70 parts per trillion (ppt) for individual or combined concentrations of PFOA and PFOS in drinking water. Recent studies indicate that exposure to PFAS at much lower exposure levels than the 2016 LHAs may result in adverse health effects, including developmental effects to fetuses and breastfed infants, cancer, liver effects, immune effects, thyroid effects, and others. In June 2022, EPA released much lower interim LHAs for PFOA and PFOS to 0.004 and 0.02 ppt, and final LHAs for perfluorobutanesulfonic acid (PFBS) and GenX chemicals to be 2000 and 10 ppt, respectively. Currently lab-based PFOA and PFOS water tests cost $300 - $400 per sample with a turnaround time of 2-3 weeks. Hence, the development of low cost field trace detection and monitoring systems for PFOS and PFOA in water is highly necessary. In this EPA Phase II program, 2Wi Tech LLC developed a low-cost fieldable sensing technology for detecting trace amounts of PFOA in water.
Summary/Accomplishments (Outputs/Outcomes):
In the Phase II program, different PFOA sensors were developed and evaluated. Their challenges for large scale fabrication and practical applications were assessed. These sensors include PFOA optical sensor, PFOA electrochemical impedance spectroscopy (EIS) sensor, and PFOA differential pulse voltammetry (DPV) sensors. Among these sensors, DPV sensor is the most sensitive one to detect the PFOA bindings by taking advantage of the amplification effect of redox species. A PFOA DPV sensor comprises an ultrathin PFOA affinitive layer deposited on the working electrode of an electrochemical sensor. Development of PFOA DPV sensors in this Phase II program has provided a promising approach for fast field screening of PFAS.
Conclusions:
Development and feasibility of PFOA sensors based on differential pulse voltammetry were demonstrated by successful completion of all the Phase II objectives. The PFOA sensing media was constructed by coating an ultrathin PFOA affinitive layer onto the flat gold electrode surface on a commercialized screen printed electrode. The sensor showed remarkable sensitivity to PFOA (1ppt level), rapid response (within minutes), wide dynamic range ranging to 1ppb and remarkable selectivity against interferences - perfluorodecanoic acid (PFDA), PFOS, perfluorooctanesulfonamide (PFOSA), and perfluorohexanoic acid (PFHxA). Capability of PFOA determination in real world samples was demonstrated using developed sensors. The determined PFOA concentrations in the samples were in well agreement with the values determined using LC-MS-MS, indicating a quick and low cost determination method for polyfluoroalkyl substances in the near future.
The market size characteristics of an emerging space are difficult to estimate, but the available information points to a large and growing opportunity for PFAS remediation and detection. The DOD alone has estimated their liability at $20B over the next 20 years, and public awareness and news stories are driving demand for private lab testing (for example, for private well testing). Prices for sample analysis at private labs can be as high as $475. Most engineering consulting firms in the space are searching for new, efficient solutions that can be deployed in the field rather than sent back to the lab.
SBIR Phase I:
Rapid Field Trace Detection of Perfluoroalkyl Substance in Water | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.