Dispersive Micro-Solid-Phase Extraction Based on Decanoic Acid Coated-Fe3O4 Nanoparticles for HPLC Analysis of Phthalate Esters in Liquor Samples

A novel, simple and low cost through coating Fe3O4 magnetic nanoparticles (MNPs) with decanoic acid were synthesized. The functionalized MNPs showed excellent dispersibility in aqueous solution and were applied to dispersive micro-solid-phase extraction(D--SPE) followed by high performance liquid chromatographic analysis for 4 phthalate esters (PAEs) including benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), and di-n-octyl phthalate (DNOP) from liquor samples. The extraction equilibrium is achieved in 1 min. The MNPs allow easy and rapid isolation of PAEs by using an external magnet, which can be reused 5 times. The 4 PAEs linear dynamic ranges were in the range of 5 to 1000 ng/mL and the correlation coefficients values were 0.9999. The limits of detection were in the range of 0.91 to 2.43 ng/mL. The influences of the adsorbent dosage and the use frequency of adsorbent, the adsorption time, the solution pH and ionic strength were investigated and optimized. The proposed method was used to determine of PAEs in liquor samples and recoveries between 88.9% and 105.4%, with the relative standard deviations were below 4.0%.