Cleanup of Soil Extracts With Various Sorbents Using the QuEChERS Technique for Gas Chromatography–Mass Spectrometry Determination of PAHs

This study examines the preparation of different soil types for polycyclic aromatic hydrocarbon (PAH) analysis, including preliminary extract purification by dispersive solid-phase extraction (dSPE) using the QuEChERS approach with various sorbents. We investigated the influence of soil matrix components and assessed the ability of different sorbents to minimize matrix effects during sample preparation. The study evaluated the performance of silica gel functionalized with N-propylethylenediamine groups (PSA), a mixture of PSA, octadecyl (C18)-bonded silica gel, and magnesium sulfate (PSA–C18–MgSO4), magnesium silicate-based Florisil, and aluminum oxide for the purification of soil extracts before gas chromatography–mass spectrometry (GC–MS) determination of PAHs. The proposed analytical procedure was used using soils with different organic matter contents. Recoveries exceeded 75% for PAHs extracted from high-humus soils and 90% for those extracted from low-humus soils. The GC–MS limits of quantification for 19 PAHs after purification of extracts from high-humus soils with Florisil or the PSA–C18–MgSO4 mixture were 5–10 μg/kg.