Per- and Polyfluoroalkyl Substances in Soils Using Agilent Bond Elut Carbon S for PFAS Solid Phase Extraction Cartridges

Significance of the topic

Per- and polyfluoroalkyl substances (PFAS) are persistent pollutants that accumulate in soils, posing risks to ecosystems and human health. Reliable low-level detection in soil is essential for environmental monitoring and regulatory compliance but is challenged by complex matrices and interferences from organic pigments and soil components.

Objectives and overview of the study

This study develops and evaluates a multicomponent LC/MS/MS method for quantifying 59 PFAS in soils using Agilent Bond Elut Carbon S SPE cartridges. The goals include achieving low nanogram-per-gram detection limits, minimizing matrix effects, and ensuring high target recovery across diverse soil types.

Methodology

• Sample extraction: 2 g of soil extracted with 10 mL of 1 % ammonia in methanol, tumbled 1 h, centrifuged, and decanted.
• Cleanup: Passthrough SPE using 250 mg Bond Elut Carbon S cartridges pre-rinsed with methanol.
• Concentration: Eluate neutralized with acetic acid, diluted with water and internal standards.
• Calibration: Six-level calibration (0.025–2.5 ng/mL) with stable isotope dilution; reporting limits set at 0.625 ng/g in 2 g soil.

Used instrumentation

• Agilent 1290 Infinity II LC with PFAS-free conversion kit
• ZORBAX RRHD Eclipse Plus C18 column (2.1 × 100 mm, 1.8 µm)
• Agilent 6470B Triple Quadrupole LC/MS with Jet Stream ESI source
• Agilent Bond Elut Carbon S SPE cartridges

Main results and discussion

• Calibration accuracy averaged >94 % across 59 PFAS; quality control standards within 75–100 % accuracy.
• Low-level spikes (0.625 ng/g): mean recovery 99.3 % (RSD 13.5 %); high-level spikes: mean recovery 99.2 % (RSD 8.5 %).
• Blank cartridge rinses and extraction blanks showed PFAS levels below reporting limits, confirming no contamination.
• Carbon S cleanup produced clear extracts with extensive pigment removal and improved chromatographic peak shapes and retention time consistency.
• Analysis of reed sedge peat detected PFBA, PFPeA, and PFHpA at low nanogram-per-gram levels; topsoil samples were below reporting limits.

Benefits and practical applications of the method

The presented workflow delivers robust, sensitive quantitation of PFAS in varied soil matrices with minimal matrix effects. High recoveries, low detection limits, and streamlined cleanup support environmental monitoring, site remediation assessment, and regulatory testing.

Future trends and possibilities for application

Advances may include adaptation to broader PFAS classes, coupling with high-resolution mass spectrometry for non-target screening, automation for high-throughput analyses, and integration into large-scale monitoring programs and soil remediation studies.

Conclusion

The Agilent Bond Elut Carbon S SPE–LC/MS/MS method provides a reliable, high-precision approach for trace PFAS analysis in soils. Efficient matrix cleanup, excellent recoveries, and low background enable confident quantitation at the ng/g level across diverse soil types.

Reference

• Weil, R.R.; Brady, N.C. The Nature and Properties of Soils, 15th Ed., Pearson, 2017.
• Zhao, L.; Wei, T. Agilent application note 5994-4765EN, 2022.
• ASTM D7968-17a; ASTM International, 2019.
• ASTM D8535-23; ASTM International, 2019.
• VITO. Compendium voor monsterneming en analyse, Vlaamse Instelling voor Technologisch Onderzoek, 2021.
• Giardina, M. Agilent application note 5994-3616EN, 2021.
• Giardina, M.; Sun, N.L. Agilent application note 5994-2999EN, 2021.
• US EPA Method 533, 2019.