Determination of phthalate esters in environmental water by magnetic Zeolitic Imidazolate Framework-8 solid-phase extraction coupled with high-performance liquid chromatography

• Rapid and efficient methodology for analyzing phthalate esters in water samples.
• Fe3O4@ZIF-8 was firstly synthesized by mercaptoacetic acids-capped Fe3O4.
• Fe3O4@ZIF-8 core–shell microspheres were used for magnetic SPE procedure.
• Optimal conditions for magnetic SPE of phthalate esters were obtained.
• The magnetic SPE method was successfully applied for real sample analysis.

In this study, the magnetic Zeolitic Imidazolate Framework-8 (ZIF-8) microspheres were successfully synthesized and applied as an effective sorbent for preconcentration of several typical phthalate esters (PAEs) from environmental water samples. Firstly, the solvothermal treatment method was used for preparation of Fe3O4 nanoparticles. Then, mercaptoacetic acid (MAA) was served as the functionalized chemical to modify Fe3O4 nanoparticles. The Fe3O4@ZIF-8 core–shell microspheres were synthesized through coating the MAA-capped Fe3O4 nanoparticles with ZIF-8. By coupling magnetic solid-phase extraction (MSPE) with high-performance liquid chromatography (HPLC), a reliable, sensitive and cost-effective method for simultaneous determination of five main PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), and dioctyl phthalate (DOP) was developed. Good linearity was observed in the range of 1.0–100.0 μg/L. The limits of detection (S/N = 3) and limits of quantification (S/N = 10) were in the range of 0.08–0.24 and 0.3–0.8 μg/L, respectively. The relative standard deviations were less than 5.5% and the accuracies of the method for the PAEs were in the range from 85.6% to 103.6%. Finally, the Fe3O4@ZIF-8 was successfully applied for rapid extraction of trace amounts of PAEs in environmental water samples.