Application note: PFAS in meat, fish, and egg by automated SPE-LC-MS/MS

PFAS determined in QuEChERS extracts of meat, fish, and egg by automated WAX-SPE cleanup coupled to LC-MS/MS with LOQs ranging from 0.01 to 0.05 μg/kg

In the analysis presented here, perfluorinated compounds are extracted from different food types (egg, fish, and meat) using a QuEChERS-like approach followed by fully automated online-SPE cleanup and LC-MS/MS determination in the ng/kg range. In addition to validating the analysis method in accordance with the EU Guidance Document, matrix-based calibrations are compared to solvent-based calibrations to illustrate the matrix effects and demonstrate the cleanup efficiency.

Online-SPE enables the injection of much larger amounts of sample extract, as well as quantitative transfer of the eluate to the HPLC mobile phase to reach the required quantification limits of 0.01 to 0.05 μg/kg.  The organic wash of the cartridges prior to elution effectively removes matrix interferences and improves the accuracy of the results. The method accuracy and trueness were demonstrated for different food types of animal origin (egg, meat, and fish). The main benefits compared to traditional SPE are simple sample handling, very low solvent consumption and excellent reproducibility.

Automated cartridge exchange as well as automated rinsing of the entire sample flow path between injections is performed. All steps of a typical SPE workflow are performed automatically including conditioning, loading, rinsing, and eluting the cartridge. Following the elution step, the cartridge is removed from the HPLC mobile phase flow path and the next sample prepared during the ongoing LC-MS/MS analysis without adding to the overall analysis time for highest possible throughput.