Dioxin 2019: Automated Sample Preparation in Method Development and Routine

Significance of the Topic

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants used in various applications for their non-stick properties. Their accumulation in water, soil and living organisms poses health and ecological risks. Monitoring PFAS at trace levels in water is essential to enforce regulatory limits and protect public health.

Objectives and Study Overview

This study aimed to develop and validate an automated sample preparation workflow for PFAS analysis in water. The focus was on minimizing background contamination, improving reproducibility and increasing throughput through unattended operation using the FREESTYLE XANA-PFAS robotic system.

Methodology and Instrumentation

The workflow employs solid-phase extraction (SPE) on the FREESTYLE XANA-PFAS platform. To reduce PFAS background, all fluorocarbon components were replaced with polyethylene or polypropylene. Water samples (500 mL) were spiked with PFAS standards at 10 ng/L. SPE cartridges were conditioned, samples loaded under pressure, washed and eluted automatically. Post-extraction, eluates were concentrated and reconstituted for analysis. Instrumentation Used:

• FREESTYLE XANA-PFAS automated SPE system
• Polypropylene and polyethylene SPE materials
• High-performance liquid chromatography coupled with mass spectrometry (HPLC-MS)

Main Results and Discussion

Recoveries for ten target PFAS ranged from 66 % to 107 % with relative standard deviations below 2.1 %, demonstrating excellent accuracy and precision. Background measurements of blank samples matched neat solvent levels, confirming negligible system-origin contamination. Chromatograms showed clean baselines and distinct PFAS peaks for spiked samples.

Benefits and Practical Applications

The automated SPE approach offers:

• Minimal manual intervention, reducing operator error
• High sample throughput (parallel processing 24/7)
• Consistently low blank levels due to non-fluorocarbon components
• Compliance with stringent regulatory limits for PFAS in water

Future Trends and Opportunities

Advances may include integration with on-line LC-MS systems for fully continuous analysis, expanded analyte panels covering emerging PFAS, and adaptation to other environmental matrices such as soil or biota. Machine learning algorithms could optimize extraction parameters for diverse sample types.

Conclusion

The FREESTYLE XANA-PFAS automated SPE workflow delivers reliable, high-throughput PFAS analysis in water with low background contamination and strong recoveries. This approach supports regulatory monitoring and routine laboratory operations while minimizing labor and variability.