Fast and Direct Detection of Perfluorocarboxlyic acids (PFCA) with SICRIT®-MS

Significance of the Topic

Per- and polyfluoroalkyl substances (PFAS), notably perfluorocarboxylic acids (PFCAs), are widely applied as surfactants, flame retardants, and coatings. Their environmental persistence drives accumulation in water, food, and consumer products, raising health concerns associated with PFOA and PFOS. Rapid, direct screening technologies are needed to enforce PFAS-free claims and to protect public health without lengthy sample preparation.

Objectives and Study Overview

This study demonstrates a direct, high-resolution MS approach for non-target screening of PFCAs in solid samples (powders, textiles) and coatings. By coupling SICRIT® soft plasma ionization with online mass spectrometry, the workflow bypasses extraction, enrichment, and chromatographic separation, enabling real-time headspace analysis.

Methodology

• Samples (coating powders, coated textiles) were presented directly in front of the MS inlet for headspace ionization.
• Negative-mode full-scan MS data were acquired over m/z 50–750 at 30,000 FWHM resolution.
• PFCA identification was based on exact-mass [M–H]– ions within a 5 ppm confidence window.

Used Instrumentation

• LTQ Orbitrap XL high-resolution mass spectrometer (Thermo Fisher).
• SICRIT® atmospheric-pressure soft plasma ion source operated at 1.5 kV, 15 kHz for negative ion mode.
• Prospective adaptation to triple quadrupole instruments for targeted MS/MS.
• Automatable headspace sampling via PAL autosampler with SICRIT® GC/SPME interface.

Key Findings and Discussion

• Homologous PFCAs from C3 to C9 were readily detected as intact [M–H]– ions with mass errors below ±1.4 ppm.
• In many commercial samples, PFOA (C8) was absent or at trace levels, indicating replacement by shorter-chain analogs.
• Direct headspace sampling provided clean spectra with minimal background and high throughput.

Practical Benefits and Applications

• Eliminates time-consuming extraction, cleanup, and chromatographic steps.
• Soft ionization preserves molecular ions for straightforward PFCA identification.
• Flexible platform suitable for routine quality control of textiles, coatings, and other solid matrices.

Future Trends and Potential Applications

• Integration with automated headspace sampling will further increase throughput.
• Deployment on various MS platforms, including triple quadrupoles for targeted quantification.
• Expansion of the workflow to other PFAS subclasses and broader environmental screening.

Conclusion

The coupling of SICRIT® soft plasma ionization with high-resolution MS offers a rapid, reagent-free approach for non-target detection of PFCAs in solids and coatings. This method streamlines PFAS analysis, supporting high-throughput screening in industrial and environmental laboratories.

References

• Larsen B.S.; Kaiser M.A. Anal. Chem. 2007, 79(11), 3966–3973.