Preparation of magnetic zeolitic imidazolate framework-67 composites for the extraction of phthalate esters from environmental water samples

In this paper, magnetic ZIF-67 composites were prepared by in-situ method and utilized in the magnetic solid-phase extraction of phthalate esters. The obtained magnetic ZIF-67 composites were in detail characterized, and the adsorbing performance was evaluated. The results showed ZIF-67 crystals in the composites were chamfered cubic shape with about 2.0 μm in diameter and Fe3O4 was attached on the surface of ZIF-67. The parameters affecting magnetic solid-phase extraction efficiency were optimized including the adsorption and desorption conditions. Under the optimum conditions, magnetic solid-phase extraction coupled with gas chromatography-mass spectrometry for analyzing seven phthalate esters in environmental water samples was established. All the analytes exhibited good linearity (1-200 ng/mL) with a correlation coefficients higher than 0.9950. The relative standard deviations were between 4.3% and 8.9%. The developed method showed high sensitivity and had a good potential for analyzing trace phthalate esters in water samples.