Bimetallic Cluster Cu7Zn2 Functionalized Copolymer Monolithic Column for Pipette Tip Micro-Solid Phase Extraction of Eight Phthalate Esters in Edible Oil

A Cu 7 Zn 2 cluster functionalized copolymer monolithic column was prepared and applied as the adsorbent of pipette tip micro-solid phase microextraction of eight phthalate esters (PAEs). The physical morphology, chemical composition, thermal stability, and specific surface area of the monolithic column were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and N 2 adsorption and desorption experiment. Cu 7 Zn 2 cluster acted as the adsorption site effectively improved the adsorption selectivity and capacity of the copolymer monolith for PAEs. The adsorption mechanism of Cu 7 Zn 2 copolymer monolith for 8 PAEs was deduced to be mainly the H-bond interaction. And, the chemical doping and copolymerization of Cu 7 Zn 2 cluster made the composite monolithic column more stable with a long service life. Under the optimized extraction conditions, a micro-solid phase extraction-high performance liquid chromatography method with ultraviolet detector (μ-SPE-HPLC-UV) was developed for the determination of 8 PAEs in edible oil. Wide linear ranges of 0.5–1000 μg/kg with correlation coefficients ( R 2 ) above 0.996 were obtained. The limits of detection (LODs) were in the range of 0.1–0.9 μg/kg. The proposed method was applied for the detection of 8 PAEs in edible oil with satisfactory recoveries between 83.5~100.2%, and the relative standard deviations were less than 8.1%. The results indicated that the Cu 7 Zn 2 functionalized copolymerized monolithic column was an ideal enrichment medium for the detection of PAEs in complex samples.