In situ synthesis of ZIF-67 in porous nanostructured copper foam substrate as a sorbent for solid phase microextraction method

Metal-organic frameworks (MOFs), a class of microporous crystalline hybrid materials was first introduced in 1995 by Yaghi et al. MOFs are formed by coordination of metal cations (or cationic clusters) with multifunctional organic linkers. The significant properties of MOFs, including large surface area and porosity, uniform pore sizes, tunable surface chemistry, structural diversity, excellent thermal and solvent stability, make MOFs highly promising in diverse applications including gas separation and storage, catalysis, chemical sensing, biomedical imaging, separation science and drug delivery. In recent years, various MOFs are synthesized and explored as separation media in analytical chemistry. To some extent, MOFs are usually synthesized via one-pot self-assembly reactions between ligands and metal salts in solutions at a certain temperature. The synthetic conditions are mild and easily controlled to obtain flexible and ideal structure. Ramification of electrodeposited metals such as copper and tin has been a very interesting topic for scientists. In particular, three-dimensional (3D) nanoramified metal deposits are suitable for sensors, batteries and fuel cells. In the present study, a simple and very rapid procedure was used to electrodeposit a copper foam coating with highly porous nanostructured walls on the surface of a copper wire. The porous structure of coating was impregnated Co and Zn for using as holder and substrate for in-situ approach for synthesis of ZIF-8 and ZIF-67. Finally the prepared fiber was used as extraction device in head space solid phase microextraction (HS-SPME). Herein benzene, toluene, ethylbenzene and xylenes were selected as the model compounds. Various experimental parameters affecting the extraction efficiency, such as desorption temperature, desorption time, salt concentration, temperature effect, equilibrium time and extraction time, were investigated and optimized.