Preparation of mixed-matrix membranes from metal organic framework (MIL-53) and poly (vinylidene fluoride) for use in determination of sulfonylurea herbicides in aqueous environments by high performance liquid chromatography

Novel mixed-matrix membranes (MMM) were prepared from metal-organic frameworks (MOF) (MIL-53) and poly (vinylidene fluoride) (PVDF), viz MIL-53-PVDF MMM, for the simultaneous dispersion membrane extraction (DME) of seven sulfonylurea herbicides (SUs) in aqueous environments followed by high performance liquid chromatography (HPLC) determination. The MIL-53-PVDF MMM was well characterized and major factors influencing DME performances were systematically investigated including membrane type, MOF dosage, eluent type, solution pH, extraction/elution time and salinity, etc. Under optimal conditions, the MIL-53-PVDF MMM based DME coupled with HPLC exhibited excellent linearity within 0.03-10 mu g L-1 for chlorimuronethyl and 0.01-10 mu g L-1 for other six SUs individual. High enrichment factor of 250 was obtained, as well as low detection limits and quantification limits ranged from 3.75 to 10.30 ng L-1 and 12.49-34.30 ng L-1, respectively. Furthermore, the method attained high recoveries of 77.20-111.00% at three spiking levels of SUs, with relative standard deviations of 1.28-14.67% in tap water, seawater and surface water samples. Additionally, the MMM was readily separated from water and well regenerated, and could keep about 80% recovery after 25 cycles. Compared to that reported extraction materials, the MIL-53-PVDF MMM possessed the advantages of high enrichment ability, excellent reusability, good practicality and easy separation, indicating it was a promising alternative for the enrichment of SUs from aqueous environments. (C) 2019 Elsevier Inc. All rights reserved.