ZIF@ ZnO-Polymer Hybrid Monoliths as Sorbent for Solid-Phase Extraction of Bisphenol A

A two-step approach was utilized to prepare highly porous monolithic polymer contains metal-organic framework as a sorbent for solid-phase extraction (SPE) technique. To this end, zinc oxide (ZnO) nanoparticles has been copolymerized with vinyl monomers to prepare a macroporous monolith. The prepared monolith was converted to zeolitic imidazolate framework (ZIF) through in-situ approach [1, 2]. The obtained ZIF@ZnO hybrid monoliths were prepared in a short column format. The surface coating was measured to be 273 m2 g−1. The as prepared short column monolithic polymer was accomplished as SPE for preconcentration of trace levels of bisphenol A (BPA) as model compound in environmental water samples. The model analyte was analyzed by high performance liquid chromatography-diode array detection (HPLC-DAD). The different factors affecting the extraction efficiency of the method such as sample volume, sample solution pH, desorption solvent and desorption volume have been optimized by one at a time optimization strategy. Under the optimum condition, linear dynamic range (LDR), limit of detection (LOD), enrichment factor (EF) and precision were determined. The LDR was in the range of 1–200 μg L-1 with a good coefficient of determination (R2 = 0.9947). The LOD (S/N = 3) and the LOQ (S/N = 10) were 0.24 and 0.72 μg L-1, respectively. The relative standard deviation (RSD) was also investigated by analysing three spiked water samples at two different concentration levels (10 μg L-1 and 100 μg L-1). The obtained RSDs were in the range of 3.9–4.3%. The EF value was obtained to be 28.

Keywords:

Solid-phase extraction , Porous organic polymers , Zinc oxide nanoparticles , Metal−organic frameworks , Monolithic columns , Pollutant extraction