Enhanced Identification Confidence and Specificity for PFAS Analysis Using Cyclic Ion Mobility Mass Spectrometry Collision Cross Sections

Importance of the Topic

Per and polyfluoroalkyl substances accumulate in the environment and human tissues posing health risks. Regulatory limits tighten globally yet emerging PFAS require advanced screening techniques. Enhancing identification confidence is critical for environmental monitoring and public health.

Objectives and Study Overview

This study evaluates cyclic ion mobility mass spectrometry and collision cross section values to improve specificity in non targeted PFAS screening. The aim is to assess reproducibility across sites and compare results to published drift tube IMS data.

Methodology and Instrumentation

The non targeted workflow combines ultra high performance liquid chromatography with cyclic ion mobility separation prior to time of flight MS analysis. Samples included mixed PFAS standards and an internal PFAS library covering 130 compounds. CCS calibration is integrated in routine mass calibration. Data were processed with driftScope and waters connect informatics platforms.
Used Instrumentation

• ACQUITY Premier UPLC System with PFAS Kit and Atlantis Premier BEH C18 AX Isolator Column
• SELECT SERIES Cyclic IMS Mass Spectrometer
• MassLynx MS Software and waters connect Data Processing

Key Findings and Discussion

Cyclic IMS produced CCS values with less than one percent deviation compared to the reference library and between laboratory sites. Intra site and inter site reproducibility yielded RMS deviations below one percent. Comparison with drift tube IMS data showed no significant difference at the 95 percent confidence level and an overall deviation of 0.62 percent. A linear quantitation range for PFOS was demonstrated over four and a half orders of magnitude.

Benefits and Practical Applications

• Increased identification specificity by combining m/z retention time and CCS metrics
• Reliable non targeted screening for known unknowns and transformation products
• Retrospective data analysis based on stored CCS values
• Standardized results across different ion mobility technologies

Future Trends and Opportunities

Expansion of comprehensive CCS libraries for emerging PFAS analytics. Advances in high resolution IMS platforms will enable faster screening in complex environmental matrices. Integration into routine regulatory monitoring workflows.

Conclusion

Cyclic ion mobility MS and measured CCS values provide a robust additional identification dimension for PFAS analysis. Reproducible results across multiple sites and alignment with drift tube CCS data support its application in environmental monitoring and risk assessment.

References

1. US EPA Method 1633 Determination of PFAS in Drinking Water January 2024
2. Directive EU 2020 2184 on Quality of Water Intended for Human Consumption December 2020
3. ASTM D8241 Determination of PFAS in Aqueous Matrices by LCMSMS 2022
4. US EPA Chemistry Dashboard PFASSTRUCT board Accessed March 20 2024
5. Stecconi T Tavoloni T Stramenga A Talanta 2024 266 125054
6. Dreolin N Adams S Waters Application Note 720008219 2024
7. Waters Application Note 720007413 2021
8. Dodds JN Hopkins ZR Knappe DRU Baker ES Analytical Chemistry 2020 92 4427
9. Waters PFAS Analysis Kit User Guide 720006689