Determination of Various PFAS in Egg Matrix Using Stacked Injection On-line SPE Coupled to LC-MS/MS

Importance of the Topic

This section describes why accurate monitoring of per- and polyfluoroalkyl substances in egg matrices is vital due to their persistence, widespread environmental occurrence and food safety concerns.

Study Objectives and Overview

The application note aims to develop a streamlined workflow for quantifying 27 PFAS in eggs using a QuEChERS extraction followed by on-line SPE with stacked injection, delivering sensitive and reproducible results.

Methodology

Egg samples were spiked with isotopically labelled standards and extracted via the QuEChERS AOAC method. A stacked injection approach was employed on the SIL-40 autosampler to introduce five sequential 10 μL aliquots onto an on-line SPE trap, enhancing sensitivity by concentrating analytes. Separation was achieved on a Shim-pack Scepter C18 column using a gradient of ammonium acetate in water and methanol. Detection was performed on the LCMS-8060NX in negative ESI with MRM transitions, using solvent delay columns to minimize background PFAS from system components. Matrix-matched calibration covered 0.001–1 ng/mL with R² > 0.98 for all targets.

Used Instrumentation

• Shimadzu LCMS-8060NX triple quadrupole mass spectrometer
• Nexera X3 UHPLC system
• SIL-40 autosampler with stacked injection
• EVOLUTE Express ABN on-line SPE cartridge
• Shim-pack GIST HP C18-AQ delay column
• Shim-pack Scepter C18 analytical column (2.1 × 50 mm, 1.9 μm)

Main Results and Discussion

Calibration curves exhibited excellent linearity (R² > 0.98). Limits of quantification reached sub-ng/mL levels. Reproducibility of spiked samples showed RSD values below 20% for most PFAS at both 0.01 and 0.1 ng/mL. Analysis of real egg samples detected multiple PFAS, including PFBA, PFBS, PFDA, PFDoDA, PFHpA, PFHxS, PFNA, PFOA and PFOS at concentrations up to hundreds of pg/mL.

Benefits and Practical Applications

• Single-vendor integration for UHPLC and MS enhances system compatibility
• Minimal sample preparation reduces handling time and contamination risk
• Stacked injection combined with on-line SPE boosts sensitivity without extensive solvent consumption
• Suitable for routine food safety and environmental monitoring of PFAS in complex matrices

Future Trends and Opportunities

Adapting this workflow to other food and environmental samples may broaden PFAS surveillance. Advances in high-resolution MS could enable non-target screening of emerging PFAS. Automation of sample prep and data analysis will support high-throughput, regulatory-compliant testing. Incorporation of green extraction techniques and micro-SPE formats may reduce solvent usage further.

Conclusion

The described method provides a fast, robust and sensitive solution for quantifying a broad panel of PFAS in egg matrices. On-line SPE with stacked injection on the LCMS-8060NX/Nexera X3 platform delivers high throughput and reproducibility, meeting the demands of modern food safety laboratories.

References

Grüning A. Determination of Various PFAS in Egg Matrix Using Stacked Injection On-line SPE Coupled to LC-MS/MS. Shimadzu Application News, First Edition: Aug. 2023.