Developed magnetic multiporous 3D N-Co@C/HCF as efficient sorbent for the extraction of five trace phthalate esters.

A three-dimensional (3D) magnetic porous N-Co@carbon dodecahedron/hierarchical carbon framework (3D N-Co@C/HCF) hybrid has been successfully synthesized by integration of the ZIF-67 into HCF and then calcination under an inert gas (N2). 3D N-Co@C/HCF as magnetic sorbent show good extraction ability for phthalate esters (PAEs: dibutyl phthalate (DBP), dimethyl phthalate (DMP), dicyclohexyl phthalate (DCHP), butyl benzyl phthalate (BBP), diethyl phthalate (DEP)). This is attributed not only to the abundant adsorption sites (due to the presence of large specific surface area) and the extremely strong π-conjugated system of 3D N-Co@C/HCF, but also to sufficient contact spaces and facile transport channels (ascribe to the interconnected hierarchical 3D porous structure) between targets and the material. Furthermore, 3D N-Co@C/HCF possesses excellent magnetism and structure stability for maximizing reuse of sorbent, which is applied as sorbent for disperse magnetic solid-phase extraction (d-MSPE) of five PAEs in the real samples. Under optimized condition, a facile d-MSPE coupled to HPLC-UV detection was developed for the extraction and determination of trace PAEs in real samples. This method revealed a high enhancement factor (230-281), wide linear range (0.2-100 ng mL-1), lower the limits of detection (0.023-0.113 ng mL-1) and satisfactory recoveries (87.1-107.2%) with the relative standard deviation (RSD) (n = 5) less than 6% for the determination of PAEs in real samples.