Investigating Fire Fighter and E-waste Handlers Exposure to PFAS Using Liquid Chromatography and Cyclic Ion Mobility Mass Spectrometry

Significance of the Topic

PFAS exposure is a critical health concern due to persistence, bioaccumulation and links to disease. Among high-risk groups, firefighters and e-waste handlers face occupational PFAS contact. Monitoring PFAS in human serum informs exposure pathways and supports risk mitigation.

Objectives and Study Overview

This investigation aimed to apply LC-cIM-MS to non-targeted PFAS profiling in serum samples from Ghanaian firefighters and e-waste handlers. Key goals included detection of linear and branched PFAS isomers, improving identification specificity and assessing occupational exposure profiles.

Methodology

A 22-minute reversed-phase gradient separated analytes prior to cyclic ion mobility mass spectrometry with two resolution settings (R≈65, R≈145). Human serum samples underwent solid-phase extraction using 96-well µElution plates with mixed-mode polymeric sorbents. Detailed conditions and ethics approvals were in prior publications.

Instrumentation Used

• Waters SELECT SERIES Cyclic IMS System
• Reversed-phase LC setup (22 min gradient)
• High-resolution quadrupole mass spectrometer with cyclic ion mobility cell
• Solid-phase extraction 96-well µElution plates

Main Results and Discussion

Cyclic ion mobility separation enhanced peak capacity and generated collision cross section (CCS) values matching library references within ΔCCS<1%. In e-waste handler serum, PFOA, PFOS and 6:2 FTS were identified. Firefighter samples revealed PFHxS, PFOS, PFHpS and PFNA. Characteristic CCS fingerprints enabled distinction of branched isomers of PFOS and PFOA, confirmed by literature CCS comparisons (ΔCCS<0.6%). Ion mobility conformer profiles further supported low-abundance PFCA identification without relying on product ions.

Benefits and Practical Applications

• Improved specificity reduces false positives from isobaric interferences.
• Non-targeted LC-cIM-MS allows comprehensive PFAS screening in complex biofluids.
• CCS databases enable routine identification of emerging PFAS isomers.
• Occupational exposure assessment informs safety guidelines for firefighters and e-waste workers.

Future Trends and Applications

Advances in cyclic ion mobility may further refine isomer separation and quantification. Integration with high-throughput workflows can support large-scale biomonitoring. Expanding CCS libraries for novel PFAS will enhance screening. Potential applications include environmental surveillance, regulatory compliance and personalized exposure assessment.

Conclusion

The study demonstrates that LC-cIM-MS offers robust, high-resolution PFAS analysis in human serum, effectively resolving challenging isomers and supporting occupational exposure assessment. The approach enables reliable identification of known and emerging PFAS, aiding public health and regulatory efforts.

References

• McCullagh M et al. Enhanced Identification Confidence and Specificity for PFAS Analysis Using Cyclic Ion Mobility Mass Spectrometry Collision Cross Sections. Waters Application Note 720008536, 2025.
• McCullagh M et al. Combining Pattern Analysis and Cyclic Ion Mobility Mass Spectrometry to Research PFAS Exposure in E-waste Handlers. Waters Application Note 720008784, 2025.
• McCullagh M et al. Use of Cyclic Ion Mobility to Enhance Specificity for Branched-PFAS Isomer Analysis. Waters Application Note 720007823, 2025.