Facile magnetization of covalent organic framework for solid-phase extraction of 15 phthalate esters in beverage samples

Recent developments of monolithic and open‐tubular capillary electrochromatography (2017–2019)

“…COFs, which are porous crystalline materials, compose of organic building blocks by strong covalent bonds including B─C─O, B─O─B, N═N, and C═N. COFs possess many useful properties, such as low density, controllable pore size, large surface area, and distinguished thermal stability, endowing them great potential as a stationary phase in CEC separation . Schiff base networks (SNWs), as a class of COFs, was prepared by melamine and tri‐aldehydes in a “one‐pot” poly‐condensation approach reported by Schwab and co‐workers in 2009 .…”

Covalent Organic Frameworks in Sample Preparation

“…In this sense, the combination of m-NPs with COFs as sorbents in m-dSPE procedures constitutes the main application of COFs as sorbents by far. As can be seen in Table 2 , magnetic COFs have been applied for the extraction of a wide variety of analytes, including polycyclic aromatic hydrocarbons (PAHs) [ 61 , 63 , 66 , 71 ], phthalic acid esters (PAEs) [ 64 , 69 , 78 , 86 ], perfluorinated compounds [ 65 , 91 ], hydroxylated polychlorinated biphenyls (PCBs) [ 68 ], phenolic compounds [ 67 , 72 , 76 ], estrogenic compounds [ 70 , 72 ], fluoroquinolones [ 73 , 88 ], dyes [ 74 ], antibiotics [ 75 , 80 ], heterocyclic aromatic amines (HAAs) [ 77 , 83 ], hydroxylated PAHs [ 79 ] and pesticides [ 81 , 82 , 84 , 90 ] originating from, among other places, environmental samples (water [ 61 , 63 , 65 , 66 , 80 , 82 ] and soils [ 63 ]), biological sources (rat plasma [ 62 ], human serum [ 67 , 68 ], human plasma [ 69 , 73 ], and human urine [ 70 , 77 , 79 , …”

“…Regarding the building blocks used for the syntheses of magnetic COFs, in a similar way as previously mentioned for dSPE, a wide variety of building blocks can be found, since their selection depends in a certain way on the analytes to be extracted. However, what is clear is that the couple Tp and BD has been the preferred building block combination in m-dSPE procedures by far [ 66 , 72 , 75 , 77 , 85 , 86 , 88 ]. Although this has been the most usual, up to seventeen different combinations have been used with a total of twenty-three different building blocks.…”

“…Regarding the magnetization step, Fe 3 O 4 m-NPs have been the most used without any doubt [ 61 , 62 , 63 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 85 , 86 , 87 , 88 , 89 , 90 , 91 ], although Ni [ 64 , 84 ], Fe 2 O 3 [ 65 ] and CoFe 2 O 4 [ 83 ] have also been applied. As previously mentioned, a wide variety of synthetic routes have been used to obtain different magnetic COFs, it being almost possible to find a procedure for each application.…”

Synthesis of magnetic metal organic framework/covalent organic framework hybrid materials as adsorbents for magnetic solid‐phase extraction of four endocrine‐disrupting chemicals from milk samples

“…Covalent organic frameworks (COFs), a type of rapidly expanding porous crystalline polymers composed of organic molecules and linkers, have attracted much attention due to their large surface area, range of topological structures, tunable pore architectures, and diverse functionalities including π‐π stacking and hydrogen‐bonding interactions, which make them potential candidates for sample pretreatment 13–15 . However, the use of COFs is hampered by lower selectivity and stability when applied to complex samples, which can be effectively improved through their functional modification 16,17 …”