New sample treatment for the determination of alkylphenols and alkylphenol ethoxylates in agricultural soils

A new sample treatment for alkylphenols (AP) and alkylphenol ethoxylates (APEO) determination in agricultural soil samples has been developed. In a first stage these compounds were isolated from soil by pressurized liquid extraction (PLE) using methanol. In a second stage the extracts were cleaned up and pre-concentrated by solid-phase extraction (SPE) using ENV + cartridges. The effect of different variables on PLE and SPE was also studied. In the last place, separation and quantification of analytes were performed by liquid chromatography with fluorescence detection (LC–FD) and gas chromatography coupled to mass spectrometry (GC–MS). Quantification limits (QL) ranged from 20 to 200 ng g−1 for LC–FD and from 3 to 126 ng g−1 for GC–MS. This method was satisfactorily applied in a study field designed to evaluate the environmental behaviour of APEOs in agricultural soils.