A Magnetic Zeolitic Imidazolate Framework Nanohybrid for Fast and Efficient Extraction of Clothianidin, Imidacloprid, Acetamiprid, and Thiacloprid in Water

A magnetic zeolitic imidazolate framework nanohybrid (Fe3O4/ZIF-8) was synthesized and applied as an efficient magnetic solid-phase extraction (MSPE) adsorbent for fast adsorption and separation of clothianidin, imidacloprid, acetamiprid, and thiacloprid from various water samples. Fe3O4 and ZIF-8 were combined via a simple modified in situ method and the obtained nanohybrid (Fe3O4/ZIF-8) showed both excellent adsorption capacity and convenient magnetic property. ZIF-8 was found to play a dominant role in adsorbing the analytes and pi-pi interaction was found to be the main adsorption mechanism of analytes by Fe3O4/ZIF-8. Parameters affecting the MSPE efficiency, such as the Fe3O4 amount loaded onto the ZIF-8, salt and pH of the sample solution, extraction time, and the type and volume of desorption solvent, were systematically evaluated. Under the optimum conditions, the developed MSPE coupled with LC-MS/MS achieved good linearities (R-2 > 0.9940) in the range of 10-800 mu g L-1 with low limits of detection (0.03-0.3 mu g L-1) and satisfactory recoveries of 79.5-108.2% with relative standard deviations (RSDs) <10%. The method was successfully applied to monitor various water samples and conclusively highlighted the excellent flexibility and practicability of Fe3O4/ZIF-8 for analyzing emerging environmental contaminants in various types of water samples.