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

Abstract

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.