Long Term Robustness of the Agilent 6495D LC/MS for PFAS Analysis

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants regulated globally. Analytical workflows demand high sensitivity, reproducibility, and uptime when monitoring PFAS residues in complex matrices such as food, soil, and biota.

Objectives and Overview of the Study

This study presents a stress test of the Agilent 6495D triple quadrupole LC/MS system with Jet Stream electrospray ionization (AJS-ESI) to assess long-term robustness during continuous PFAS analysis in salmon extract. Over 13,700 consecutive injections were performed without maintenance to evaluate system stability and quantitation precision.

Methodology and Sample Preparation

Salmon samples were homogenized and extracted using water and acetonitrile with QuEChERS salts, followed by cleanup on an EMR PFAS Food II cartridge. Extracts were spiked with native and isotopically labeled PFAS standards at ~0.5 ppb. A rapid 3-minute gradient on a C18 column and high-throughput LC parameters were employed.

Used Instrumentation

• Agilent 1290 Infinity II LC System with ZORBAX RRHD Eclipse Plus C18 and InfinityLab PFC Delay columns
• Agilent 6495D triple quadrupole LC/TQ mass spectrometer
• Agilent Jet Stream electrospray ionization (AJS-ESI) source with iFunnel technology

Results and Discussion

Throughout ~3 weeks of continuous operation and 138 mL of salmon extract, the system maintained quantitative precision with raw peak area RSDs ≤ 7.5 % for PFAS analytes and ≤ 5 % after internal standard correction. Mass axis and peak width calibrations remained within specifications, and overlaid MRM chromatograms after every 10 mL of extract showed consistent signal shapes and intensities. No routine cleaning or tuning was required, and minimal inlet contamination was observed.

Benefits and Practical Applications

• High-throughput PFAS screening with sustained sensitivity
• Reduced downtime and maintenance costs
• Reliable quantitation in challenging matrices such as food and environmental samples

Future Trends and Opportunities

Emerging developments may include automated source cleaning, expanded PFAS compound coverage, integration with high-resolution and data-processing workflows, and real-time field monitoring. Advanced software and AI-driven quality control could further enhance long-term performance.

Conclusion

The Agilent 6495D LC/TQ demonstrated exceptional robustness for PFAS analysis under extended stress conditions. Its ability to sustain consistent performance over thousands of injections without maintenance makes it an ideal solution for laboratories requiring continuous high-throughput and reliable PFAS quantitation.

Reference

• Weidner P, Zekavat B, Chevallier O, Zhao L, Fandino A. Long Term Robustness of the Agilent 6495D LC/MS for PFAS Analysis. Agilent Technologies, 2025.