Magnetic solid phase extraction based on dodecyl functionalization of magnetic ferrite microspheres for determination of phthalate esters in environmental water

Abstract

A fast, simple, and efficient sample pretreatment technique based on magnetic dodecyl functionalization of magnetic ferrite microspheres has been developed for the extraction and pre-concentration of phthalate esters from environmental water prior to high-performance liquid chromatography analysis. The magnetic composite microspheres were prepared using Fe3O4 microspheres as magnetic core and silica as a shell with the surface-modified with C12 material. The structure of the prepared microspheres was characterized by Fourier transform infrared spectrometry, scanning electron microscopy, and vibrating sample magnetometry. Three kinds of phthalate esters were selected as model compounds to optimize the main parameters that affect extraction efficiencies, such as adsorbent dosage, sample volume, salt addition, extraction time, pH of sample solution, desorption time, eluent type, and volume. Under the optimal conditions, limits of detection (LODs) of 0.025–0.107 ng mL−1 and limits of quantification (LOQs) of 0.083–0.357 ng mL−1 were achieved. The developed method was applied for the detection of the three PAEs in a spiked sample of river water, and satisfactory recoveries in the range of 76.3–98.9% were obtained with good repeatability (RSD < 4.7%). The entire analysis process can be completed in about 30 min.