Facile Preparation of Hydrophilic-Bifunctional-Groups Modified Magnetic Microspheres as a Novel Matrix for Detection of Phthalate Esters from Human Plasma Samples

A novel hydrophilic magnetic solid phase extraction (MSPE) sorbent with imidazole-based ionic liquid and adenosine tri-phosphate (ATP) as bifunctional groups, polydopamine (PDA) as an intermediate layer, Fe3O4 as a magnetic core (Fe3O4@PDA-ATP@IL) was prepared and applied for selective extraction of phthalic acid esters (PAEs). The resultant Fe3O4@PDA-ATP@IL performed strong paramagnetic response, excellent water dispersibility, high capacity and selectivity toward PAEs. This strategy exhibited wide linearity (50-8000 ng/mL), low limit of detection (0.02-0.80 ng/mL), good recovery (92.3-105.3%) and good precision (intra-day RSDs less than 4.8%, inter-day RSDs less than 6.7%). More encouragingly, under the optimized conditions, the prepared microspheres were applied to analyze nine PAEs in human plasma samples and achieved satisfactory results. The proposed method may open new avenues for analysis of aromatic chemicals in real samples.