Highly sensitive targeted and non-targeted HPLC-MS analysis of PFAS

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants known for their long lifetime and mobility. Their stability leads to accumulation in groundwater and soil, with proven harmful health effects. To mitigate environmental pollution, several PFAS compounds, such as perfluorooctanoic acid (PFOA), perfluorohexanesulfonic acid (PFHxS), and long-chain perfluoroalkyl carboxylic acids (C9-C14), are now regulated. This technical note presents a method for identifying and quantifying PFAS using a YMC-Triart C18 HPLC column. This column, based on a robust hybrid silica particle, offers enhanced separation of isomers and improved analytical performance when coupled with mass spectrometry.

PFAS standards were analysed at concentrations ranging from 5–100 ng/mL. The standards could be well resolved by the YMC-Triart column. Notably, partial separation of PFOS and PFHxS isomers within 10 seconds facilitated fragmentation pattern analysis for structural elucidation.

For perfluoroalkyl carboxylic acids (PFCAs), higher peak intensities were observed for longer carbon chains as expected. Additionally, CO2-loss ions exhibited remarkably higher intensities than the primary molecular ions. Calibration curves demonstrated a linear quantification range, and carry-over tests confirmed no residual analytes after injections of 100 ng/mL. These results highlight the YMC-Triart C18 column’s suitability for robust PFAS analysis.

Non-targeted analysis in a soil extract

To evaluate performance in complex matrices, a soil extract from a contaminated site (Brilon-Scharfenberg, Germany; from the scientific publication of Zweigle et al. [1]) was analysed. Total ion chromatograms (TICs) from triplicate measurements (Figure 2) revealed consistent profiles, despite the high matrix complexity.

The YMC-Triart C18 column achieved effective separation of PFAS (Figure 3), including improved partial resolution of isomers compared to Zweigle et al. [1]. For instance, SF₅(CF₂)₉SO₃ isomers were separated, enabling the acquisition of distinct fragmentation spectra. Ion traces at 575 s and 600 s revealed differences in fragmentation patterns, indicating structural variations. The larger fragments in longer retention indicate an exclusively linear isomer. Specifically, the shorter retention time and the smaller fragments suggest a branched isomer or a differently positioned SF5-group.

Conclusion

The YMC-Triart C18 column demonstrates robust performance for PFAS analysis. It delivers:

• Efficient separation of key PFAS standards with linear quantification.
• Reproducible results in complex matrices, such as soil extracts.
• Improved isomer separation, enabling structural elucidation through distinct fragmentation patterns.

The column provides a reliable and enhanced approach to targeted and non-targeted PFAS analysis, supporting environmental monitoring and regulatory compliance.

Download the Technical Note for full details.

References:

[1] Environ. Sci. Technol. 2023, 57, 6647−6655.