Updated Guidance for Communicating PFAS Identification Confidence with Ion Mobility Spectrometry

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Per- and polyfluoroalkyl substances (PFAS) are globally detected in various matrices, including consumer products, human blood, and drinking water.
• Non-targeted analyses (NTA) are increasingly used to identify PFAS in environmental and biological samples.
• Current methods for reporting identified PFAS lack consistency, hindering comprehensive understanding.

Purpose of the Study:

• To investigate current practices for reporting confidence levels of PFAS identified by LC-GC-IMS-HRMS.
• To propose a unified and automated confidence level guidance for PFAS identification.
• To incorporate PFAS-specific attributes and ion mobility spectrometry collision cross section (CCS) values into the proposed guidance.

Main Methods:

• Review of current practices for PFAS confidence level reporting.
• Development of a unified confidence level framework.
• Integration of PFAS-specific attributes and CCS values from ion mobility spectrometry (IMS) coupled with high-resolution mass spectrometry (HRMS).

Main Results:

• Identified inconsistencies in current PFAS reporting practices.
• Proposed a simplified, unified confidence level guidance system.
• Demonstrated the utility of incorporating CCS values for enhanced PFAS identification.

Conclusions:

• A unified confidence level system is crucial for consistent PFAS reporting.
• The proposed guidance enhances objectivity and reliability in PFAS identification.
• This framework supports more accurate environmental and human health risk assessments related to PFAS contamination.