Enhanced Reliability for Long-Term PFAS Analysis with the Xevo TQ Absolute XR Mass Spectrometer

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) present persistent environmental and health risks, driving stringent regulatory requirements. Reliable long-term monitoring of PFAS in water, soil, biosolids, and leachate is critical to meet EPA Method 1633 standards and ensure public safety.

Study Objectives and Overview

This study assessed the robustness and uptime of the Xevo TQ Absolute XR mass spectrometer equipped with the novel StepWave™ XR Ion Guide over a 10-week period and more than 7 000 injections. River water, biosolid, and landfill leachate matrices were analyzed to evaluate system performance under challenging sample conditions.

Methodology and Instrumentation

Sample preparation followed EPA 1633 SPE clean-up protocols for:

• River water (250 mL, spiked with native and internal standards)
• Biosolid (0.5 g reference material, diluted post-extraction)
• Landfill leachate (25 mL reference material)

LC-MS/MS analysis employed:

• UPLC: ACQUITY™ Premier System with BEH C18 and BEH C18 AX isolator columns
• Mass spectrometer: Xevo TQ Absolute XR with StepWave XR Ion Guide in ESI− mode
• Weekly 1/x weighted calibration with waters_connect™ for Quantitation
• Routine maintenance: monthly cone and column replacements, no venting except one power interruption

Results and Discussion

QC performance remained within ±30% of targets, with %RSD <8.4% across all PFAS monitored.
Spiked river water trueness values ranged 70–130% throughout the study, demonstrating stable quantitation in aqueous matrices.
Biosolid extracts yielded mean values within −6.1% of certified concentrations and %RSD ≤7.3%.
Landfill leachate analyses achieved consistent results (e.g., PFOA mean 2.52 ng/mL, %RSD 2.7%), confirming reliable detection in complex samples.

Benefits and Practical Applications

The Xevo TQ Absolute XR platform delivered:

• Continuous operation for over 7 000 injections without unscheduled downtime
• Reproducible PFAS quantitation across diverse matrices
• Streamlined data review and calibration management via waters_connect™

This enhances laboratory efficiency, reduces maintenance demands, and ensures compliance with regulatory limits.

Future Trends and Potential Applications

Emerging PFAS variants and stricter guidelines will require further advancements in sensitivity and selectivity. Automation of sample preparation, integration with high-resolution MS, and expanded informatics capabilities will support high-throughput environmental monitoring.

Conclusion

The StepWave XR Ion Guide integrated into the Xevo TQ Absolute XR mass spectrometer offers a highly reliable platform for long-term PFAS analysis. Its robust performance and minimal downtime make it well suited for laboratories aiming to meet stringent regulatory standards while maintaining operational efficiency.

Reference

• US Environmental Protection Agency. EPA Method 1633A, Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC-MS/MS. Dec 2024.
• Organtini KL, Rosnack KJ, Plummer C, Hancock PM, Burt O. Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Accordance with EPA 1633 Part 2: Analysis of Aqueous Matrices. Waters Application Note 720008143. Dec 2023.
• Organtini KL, Rosnack KJ, Plummer C, Hancock PM, Burt O. Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Accordance with EPA 1633 Part 3: Analysis of Soil and Tissue. Waters Application Note 720008230. Feb 2024.