Ultra Low-Level Detection of Perfluoroalkyl Substances (PFASs) Using the PFC Analysis Kit

Significance of the topic

Perfluoroalkyl substances (PFASs) are a class of fully fluorinated compounds widely used in industrial and consumer applications for their water- and oil-repellent properties. Their environmental persistence and tendency to bioaccumulate have raised significant public health and regulatory concerns. Ultra-trace analysis of PFASs in environmental, biological, and laboratory matrixes demands sensitive and contamination-free workflows to obtain reliable data.

Objectives and overview of the study

This study demonstrates the implementation of the Waters PFC Analysis Kit on the ACQUITY UPLC I-Class System coupled to the Xevo TQ-S mass spectrometer to achieve ultra-low detection limits for routine PFAS targets. Key goals include:

• Establishing a contamination-controlled UPLC-MS/MS setup
• Defining limits of detection (LODs) for a panel of common PFAS analytes
• Assessing linearity and quantitative performance across three orders of magnitude

Methodology and instrumentation

The workflow integrates components from the PFC Analysis Kit to minimize background PFAS contamination:

• Replacement of all Teflon solvent lines in the sample manager and binary solvent manager with pre-cut PEEK tubing
• Installation of an ACQUITY BEH C18 Isolator Column upstream of the analytical column
• Use of PFAS-free vials, caps, and standards supplied in the kit
• Chromatography on a 50 × 2.1 mm, 1.7 µm ACQUITY BEH C18 column with a 98:2 water:methanol (2 mM ammonium acetate) mobile phase A and methanol (2 mM ammonium acetate) mobile phase B
• Gradient elution from 10 % to 100 % B over 5.1 min at 0.65 mL/min flow rate
• Detection by Xevo TQ-S using optimized multiple reaction monitoring (MRM) transitions, collision energies, and cone voltages for each PFAS target

Main results and discussion

Using solvent standards, all targeted PFASs achieved LODs below 0.07 ng/mL (S/N ≥ 3). Notably, perfluorooctanesulfonate (PFOS) displayed an LOD of 0.0125 ng/mL, with a clear MRM signal at the detection threshold. Calibration curves for each analyte demonstrated linear response over three orders of magnitude. The combination of PFAS-free system components and the high sensitivity of the Xevo TQ-S enabled robust quantitation at ultra-trace levels.

Benefits and practical applications

The integrated PFC Analysis Kit solution offers:

• Reduced system background for more accurate trace-level PFAS measurements
• Streamlined maintenance of UPLC instruments for PFAS analysis
• Validated performance for regulatory monitoring and environmental studies
• Compatibility with existing ACQUITY UPLC models, facilitating broad adoption

Future trends and potential applications

As regulatory limits for PFASs tighten, future developments may include:

• Expansion of target panels to include emerging PFASs and transformation products
• Automated sample preparation workflows for high-throughput screening
• Integration with high-resolution mass spectrometry for non-targeted PFAS screening
• Miniaturized and field-deployable platforms for on-site monitoring

Conclusion

The Waters PFC Analysis Kit, when combined with ACQUITY UPLC I-Class and Xevo TQ-S, provides a comprehensive, ultra-sensitive solution for PFAS analysis. This approach addresses contamination challenges and delivers reliable quantitation at sub-ng/mL levels, supporting environmental monitoring, regulatory compliance, and research applications.