Anionic surfactant micelle-mediated extraction coupled with dispersive magnetic microextraction for the determination of phthalate esters.

A novel and easy two-step microextraction technique combining anionic surfactant coacervation phase (CAP) extraction and dispersive microsolid-phase extraction (D-μ-SPE) was developed for the high-performance liquid chromatography-ultraviolet detection to determination of phthalate esters (PEs) in water samples. The method started with the phase separation of sodium dodecylbenzenesulfonic acid (SDBSA) obtained by adding NaCl, whereas the target analytes were extracted in the CAP. The CAP was then retrieved using diatomaceous earth-supported magnetite nanoparticles. The effects of solution acidity, SDBSA, and electrolyte concentration, extraction time, magnetic material quantity, and elution solvent volume were discussed. Under optimal extraction conditions, the extraction recoveries ranged from 48.6 to 84.8%, and relative standard deviations ranged from 3.9 to 5.7% (n = 10). The detection limits ranged from 0.5 to 5.0 ng mL(-1) for the five PEs. The proposed method was used to determine the five PEs in the water samples and recoveries between 85.7 and 105.5%.