Research progress in the application of metal-organic framework-derived materials in sample pretreatment

Pre-processing technology plays a vital role in the entire analysis process of complex samples (such as biological, food and environmental samples)

Various pretreatment techniques such as solid phase extraction, solid phase microextraction, magnetic solid phase extraction, stir bar solid phase extraction and in-tube solid phase extraction, etc.

Metal-organic frameworks (MOFs) are porous crystals with a periodic and infinitely extending framework structure formed by self-assembly of inorganic metal ions (or metal clusters) as nodes or centers.

Since the coordination bond between the metal ion and the organic ligand in the MOFs material is unstable under the influence of the external environment, MOFs can be used as a precursor for the synthesis of porous carbon materials or metal oxide/carbon composite materials under high temperature and different atmosphere conditions.

As a simple porous carbon material, MOFs derivatives are used as adsorbents for sample pretreatment and have the following advantages:

Porous carbon materials derived from MOFs generally have a larger specific surface area than other carbon-based materials, which is beneficial to increase the contact area between the material and the target, and increase the extraction capacity and extraction efficiency;

Its micro porous structure is easy to adjust (control the temperature and time during the pyrolysis process, gas atmosphere and heating rate, etc.

The metal active sites can be evenly distributed

Heteroatoms such as nitrogen and sulfur are easily doped on the porous carbon framework derived from MOFs.

　　This article will combine the related research work reported by this research group and other researchers at home and abroad in recent years, summarize and comment on the preparation of MOFs derivatives and the pretreatment technology based on MOFs derivatives, and prospects for its development prospects

　　1 Application of MOFs derivatives in the field of dispersive solid phase extraction

　　2 Application of MOFs derivatives in the field of magnetic solid phase extraction

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　　3 Application of MOFs derivatives in the field of solid phase microextraction

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　　4 Application of MOFs derivatives in other pretreatment technologies

　　Conclusion and Outlook

　　MOFs derivatives are easy to prepare, have unique microstructures and excellent properties.

　　Although a variety of MOFs derivatives have been developed for application in the field of sample pretreatment, they have poor targeted adsorption capacity for target analytes.

　　For example, MOFs derivatives with specific pore structures can be designed by using SiO2, polymers, surfactants, etc.

　　In addition, exploring some methods that can increase the specific surface area of ​​MOFs derivatives will also play a positive role in promoting the application of pretreatment technology

　　The low yield of MOFs derivatives (usually 13%-21%) is also one of the reasons that limit their large-scale application
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Although the pyrolysis of the composite of MOFs and other carbon sources can increase its yield, the presence of additional carbon sources will affect the microstructure and adsorption active sites of MOFs derivatives, thereby affecting their adsorption performance
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　　Therefore, compared with MOFs, MOFs derivatives have more room for exploration in the development and application of pretreatment fields
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