Using Spectral Databases to Identify Potential PFAS Compounds (2nd Edition)

Per- and Polyfluoroalkyl substances (PFAS) are a class of fluorinated organic compounds known colloquially as “forever chemicals” because of their environmental persistence. A universally accepted PFAS definition does not currently exist. Various organizations, such as the U.S. Environmental Protection Agency (EPA) and the Organisation for Economic Co-operation and Development (OECD), are using different criteria.¹

In response to customer requests for PFAS compound coverage in our spectral libraries and specific databases, an updated EPA method was used in the determination². The most current EPA PFAS substructure query (Figure 1) was used to identify potential PFAS compounds in Wiley's Spectral Libraries. Additional information regarding the current EPA PFAS substructure query can be found at the EPA CompTox Chemicals Dashboard

Wiley: Using Spectral Databases to Identify Potential PFAS Compounds (2nd Edition) - Figure 1.

Figure 1. In Wiley's KnowItAll software³ (ChemWindow application), the current EPA PFAS substructure query was drawn and searched (SearchIt application) against the KnowItAll reference libraries to identify potential PFAS compounds in each library. The resulting PFAS compound coverage is listed below.

PFAS Compound Coverage in the KnowItAll Spectral Libraries.

Spectral Library Collections - Number of Spectral Records

• KnowItAll IR Spectral Libraries - 1,093

• KnowItAll Raman Spectral Libraries - 98

• KnowItAll Wiley Mass Spectral Libraries - 7,965

• KnowItAll NMR Spectral Libraries - 14,126

• KnowItAll UV-Vis Spectral Libraries - 26

• Spectral Libraries – Total - 23,308

Additional PFAS Compound Coverage.

Spectral Library Collections - Number of Spectral Records

• Wiley Registry of Mass Spectral Data 2023 - 7,424

• NIST 2023 (GC/MS) - 8,936

• NIST 2023 (MS/MS) - 4,158

• Spectral Libraries – Total - 20,518

In KnowItAll 2024, the most current EPA PFAS substructure query (Version 5) is located at the following file path, in the “Markush Type Structures” database [Record ID #6]:

• C:\Users\Public\Documents\Wiley\KnowItAll\ Samples\Structures\Markush Type Structures

Acknowledgements

Special thanks to the following individuals for providing additional information regarding PFAS compounds:

• Linda Gaines, Environmental Engineer in the Office of Superfund Remediation and Technology Innovation (OSRTI), Office of Land Emergency Management (OLEM), U.S. Environmental Protection Agency
• Antony Williams, Computational Chemist in the Office of Research & Development, Center for Computational Toxicology & Exposure (CCTE), U.S. Environmental Protection Agency