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• Ti4+-immobilized magnetic COF adsorbent were prepared with the help of alendronate sodium. • Alendronate sodium has bi-phosphate groups which can immobilize Ti4+ more efficiently. • The adsorbent shows high selectivity to nucleotides under various analogues. • The adsorbent can exclude biomacromolecules. • The adsorbent has high adsorption capacity and fast kinetics to nucleotides. In this work, a titanium (IV) immobilized covalent organic framework (COF) was developed and used as an efficient adsorbent for highly selective enrichment of nucleotides from human serum. Firstly, an amino-functionalized magnetic COF (Fe 3 O 4 @TpBD(NH 2) 2) was synthesized by the in situ growth strategy. Alendronate sodium (AS) was then modified on the surface of the Fe 3 O 4 @TpBD(NH 2) 2 via Schiff base reaction. Finally, Ti4+ was chelated to obtain immobilized metal ion affinity chromatography (IMAC) adsorbent (denoted as Fe 3 O 4 @COF-AS-Ti4+). Its adsorption performances toward nucleotides including adenosine triphosphate (ATP), adenosine-5′-diphosphate (ADP) and adenosine-5′-monophosphate (AMP) were investigated, their maximum adsorption capacity were 36.7, 39.0 and 49.6 μmol/g, respectively. The adsorption and desorption can be achieved very fast (in 1 min). In addition, the Fe 3 O 4 @COF-AS-Ti4+ can still selectively adsorb nucleotides in the presence of other analogues, such as nucleosides, phenols, aromatic amines and phenol amines. It can be served as a good adsorbent for selective enrichment of nucleotides and simultaneous exclusion of biomacromolecules. It has also good synthesis reproducibility and reusability. These features suggest that the Fe 3 O 4 @COF-AS-Ti4+ nanospheres are of great benefit for pretreatment prior to instrument analysis of nucleotides. [ABSTRACT FROM AUTHOR]

Porous β-CD polymer (CDP) is a good adsorbent with broad spectrum for removal of micropollutants, preparation of composites of CDP with magnetic materials is highly expected. In this work, a composite of magnetic graphene and CDP (magGO-CDP) was prepared, it was fully characterized and was used as an adsorbent to remove model pollutants, including methylene blue (MB), rhodamine B (RhB), fleroxacin (Fler), enrofloxacin (Enr), bisphenol A (BPA), bisphenol S (BPS), nabumetone (NaB) and indomethacin (Ind) in wastewater. Factors influencing the removal efficiency were studied. The removal rates of the eight pollutants can reach 101 ± 0.7 %, 94.7 ± 1.8 %, 83.3 ± 1.1 %, 91.9 ± 0.2 %, 58.9 ± 0.9 %, 77.4 ± 3.5 %, 96.2 ± 0.3 % and 94.7 ± 0.8 %, respectively. Their maximum adsorption capacities are 133, 178, 185, 34.8, 362, 247, 186 and 187 mg/g, respectively. Findings from kinetic studies suggest that the pseudo-second-order model can successfully describe the overall adsorption process. The adsorbent has good capability to resist fouling of natural organic matter, and it has good reusability and can be recycled for at least five times. It has a higher adsorption capacity than that of previously reported materials and could achieve good removal efficiency with smaller adsorbent dosage and shorter time. It was also used for simultaneous removal of multiple pollutants and removal of pollutants in simulated wastewater with satisfactory results. The magGO-CDP can serve as a promising candidate for wastewater remediation. The strategy for preparing the composite of CDP and magGO can be straightly extended to other matrixes to produce high performance adsorbents. [Display omitted] • A composite of magnetic graphene/β-cyclodextrin polymer (magGO-CDP) was prepared. • magGO-CDP had high adsorption capacity for pollutants up to 362 mg bisphenol A/g. • Removal efficiency of > 90 % can be achieved with 0.5 g/L adsorbent dosage in 1 min. • Simultaneous removal of multiple pollutants and simulated wastewater remediation. • The strategy can be extended to prepare composites of CDP and other matrixes. [ABSTRACT FROM AUTHOR]

Scheme. 1. Illustration of (a) static procedure and (b) dynamic procedure for analysis of naphthalene and its derivatives. [Display omitted] • MDA was used as a linker monomer to prepare flexible COFs for the first time. • TpMDA showed high removal efficiency to naphthalene and its derivatives. • TpMDA remained well adsorption capacity after 10 times desorption/adsorption cycles. • Possible adsorption mechanisms were discussed in detail. • TpMDA had promising applications in the removal of linear and planar PAHs. In this work, a flexible covalent organic framework (named TpMDA) was prepared by cheap 4,4′-diaminodiphenylmethane (MDA) monomer with flexible methylene groups. TpMDA could realize efficient removal of naphthalene and its derivatives (NAs) from environmental water samples through hydrophobic, π-π and electrostatic interactions. The superior adsorption and desorption performance of TpMDA was confirmed by static and dynamic adsorption/desorption experiments. It can be seen from the fitting results of the adsorption experiments that the adsorption of NAs was a spontaneous, endothermic, and comprehensive adsorption process that included both physical and chemical adsorption. The average removal efficiency of Nap, 1-Anap, 1-Nnap, 1-Naa and Npx by TpMDA from the four batches were 92.1 %, 86.9 %, 93.8 %, 75.3 % and 91.8 %, respectively. The maximum adsorption capacities were 301, 120, 184, 125 and 106 mg/g, respectively. In addition, TpMDA could be reused at least 10 times without degradation of adsorption performance. The selectivity for planar and linear molecules was verified. The feasibility of practical application was verified by static/dynamic adsorption volume experiments and the application of TpMDA in different aqueous environments. In general, this work not only proposes a new idea for the preparation of flexible COFs, but also provides a promising strategy for the removal of NAs in environmental remediation. [ABSTRACT FROM AUTHOR]