Analysis of PFAS in water using Head-Space Solid Phase Microextraction-Gas Chromatography/Mass Spectrometry (HS-SPME GCMS)

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants associated with adverse health effects. Volatile PFAS in water represent a growing analytical challenge due to low concentrations and complex matrices. Reliable monitoring methods are essential for environmental surveillance, regulatory compliance and risk assessment.

Objectives and Study Overview

This study aimed to develop and validate a head-space solid phase microextraction–gas chromatography/mass spectrometry (HS-SPME GC/MS) method for the qualitative and quantitative determination of thirteen volatile PFAS in water samples. Parameters for extraction, separation and detection were optimized to achieve high sensitivity, linearity and minimal carryover.

Methodology

The optimized HS-SPME procedure uses a 50/30 µm DVB/CAR/PDMS fiber. Water samples (10 mL) with 2 % NaCl are incubated for 5 min at 50 °C, extracted for 30 min under agitation (300 rpm), and desorbed in the GC inlet at 240 °C for 7 min. Separation occurs on a SH-I-624Sil MS capillary column with a temperature program from 40 °C to 300 °C. The QP2020 NX mass spectrometer operates in full-scan (m/z 50–600) and selected ion monitoring (SIM) modes. Isotope-dilution calibration covers 2.5 to 2000 ng/L levels.

Used Instrumentation

• Shimadzu GC-2030 or Nexis GC-2030 GC system
• Shimadzu QP2020 NX single quadrupole MS
• AOC-6000 Plus autosampler with SPME module

Key Results and Discussion

All thirteen PFAS exhibited excellent linearity (R² ≥ 0.993) and response factor precision (< 20 %RSD). Laboratory blanks showed no quantifiable contamination. Carryover after the highest calibration standard was < 0.2 %. Total ion and SIM chromatograms confirmed baseline separation and consistent detection at low ng/L levels.

Benefits and Practical Applications

• Simplified sample preparation and reduced solvent use
• Cost-effective automated extraction and analysis
• High throughput screening for environmental and industrial laboratories
• Applicable to QA/QC monitoring of drinking, groundwater and surface waters

Future Trends and Opportunities

Advances in fiber coatings and MS resolution may extend this approach to non-volatile PFAS and complex matrices (soil, biota). Integration with high-resolution MS and data-driven workflows could enhance trace-level detection and structural elucidation. Expanding target lists to emerging PFAS will support evolving regulatory frameworks.

Conclusion

The developed HS-SPME GC/MS method on a Shimadzu GC/MS-QP2020 NX platform provides a robust, sensitive and reproducible tool for monitoring volatile PFAS in water. It delivers reliable quantitative performance across a broad concentration range, facilitating routine environmental analysis and regulatory compliance.