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The present study describes the trace analysis of 23 fluorinated aromatic carboxylic acids based on the dispersive solid-phase extraction (dSPE) technique using UiO-66-NH 2 MOF as efficient, recyclable sorbent, and GC-MS negative ionization mass spectrometry (NICI MS) as determination technique. All 23 fluorobenzoic acids (FBAs) were enriched, separated, and eluted in a shorter retention time; the derivatization was done by pentafluorobenzyl bromide (1% in acetone), in which the use of inorganic base K 2 CO 3 was improved by triethylamine to increase the lifespan of the GC column. The performance of UiO-66-NH 2 was evaluated by dSPE in Milli-Q water, artificial seawater, and tap water samples, and the impact of various parameters on the extraction efficiency was investigated by GC-NICI MS. The method was found to be precise, reproducible, and applicable to the seawater samples. In the linearity range, the regression value was found to be >0.98; LOD and LOQ were found to be in the range of 0.33-1.17 ng/mL and 1.23-3.33 ng/mL, respectively; and the value of the extraction efficiency was found to range between 98.45 and 104.39% for Milli-Q water samples, 69.13-105.48% for salt-rich seawater samples, and 92.56-103.50% for tap water samples with a maximum RSD value of 6.87% that confirms the applicability of the method to different water matrices., (© 2023. Springer-Verlag GmbH Germany, part of Springer Nature.)

Given the shortage of sustainable resources and the increasingly serious environmental issues in recent decades, the demand for clean technologies and sustainable feedstocks is of great interest to researchers worldwide. With regard to the fields of energy saving and environmental remediation, the key point is the development of efficient catalysts, not only in terms of facile synthesis methods, but also the benign utilization of such catalysts. This work reviews the use of metal-organic frameworks (MOFs) and MOF-based materials in these fields. The definition of MOFs and MOF-based materials will be primarily introduced followed by a brief description of the characterization and stability of MOF-related materials under the applied conditions. The greening of MOF synthesis processes will then be discussed and catalogued by benign solvents and conditions and green precursors of MOFs. Furthermore, their suitable application in sustainable catalysis will be summarized, focusing on several typical atom-economic reactions, such as the direct introduction of H 2 or O 2 and C-C bond formation. Approaches towards reducing CO 2 emission by MOF-based catalysts will be described with special emphasis on CO 2 fixation and CO 2 reduction. In addition, driven by the explosive growth of energy consumption in the last century, much research has gone into biomass, which represents a renewable alternative to fossil fuels and a sustainable carbon feedstock for chemical production. The advanced progress of biomass-related transformations is also illustrated herein. Fundamental insights into the nature of MOF-based materials as constitutionally easily recoverable heterogeneous catalysts and as supports for various active sites is thoroughly discussed. Finally, challenges facing the development of this field and the outlook for future research are presented., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

To obtain environmentally friendly antifouling agent, an effort was made to intercalate carboxymethyl chitosan into the interlayer of organic montmorillonite to prepare carboxymethyl chitosan/organic montmorillonite nanocomposites and their copper complexes. In comparison, carboxymethyl chitosan-copper complexes were also obtained. Their structures were characterized by X-ray diffaraction, transmittance electron microscopy and Fourier transform infrared, and their thermal behavior and antimicrobial activity were discussed. The results revealed that the interlayer distance of carboxymethyl chitosan/organic montmorillonite nanocomposites enlarged with the increasing mass ratio of carboxymethyl chitosan to organic montmorillonite, when the mass ratio was at 20:1, the layer spacing of carboxymethyl chitosan/organic montmorillonite nanocomposites reached the maximum of 3.68 nm. As compared to other samples, carboxymethyl chitosan/organic montmorillonite-copper nanocomposites showed much higher thermal stability and inhibitory activity against Escherichia coli, the lowest minimum inhibition concentration was only 0.0003125% (w/v). The study provides a new method to find novel antifouling agent., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Metal-organic frameworks (MOFs) possess unique properties desirable for delivery of drugs and gaseous therapeutics, but their uncharacterized interactions with cells raise increasing concerns of their safety in such biomedical applications. We evaluated the adverse effects of zinc nanoscale MOFs on the cell morphology, cytoskeleton, cell viability and expression of neurotrophin signaling pathway-associated GAP-43 protein in rat pheochromocytoma PC12 cells. At the concentration of 25 μg/ml, zinc MOFs did not significantly affect morphology, viability and membrane integrity of the cells. But at higher concentrations (over 100 μg/ml), MOFs exhibited a time- and concentration-dependent cytotoxicity, indicating their entry into the cells via endocytosis where they release Zn(2+) into the cytosol to cause increased intracellular concentration of Zn(2+). We demonstrated that the toxicity of MOFs was associated with a disrupted cellular zinc homeostasis and down-regulation of GAP-43 protein, which might be the underlying mechanism for the improved differentiation in PC12 cells. These findings highlight the importance of cytotoxic evaluation of the MOFs before their biomedical application., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Pine Kraft-AQ pulp was bleached with hydrogen peroxide catalyzed by [LMn(IV)(2) (mu-O)(3)](ClO(4))(2) at 80 degrees C for 120 min under optimum reaction conditions. The resulting bleached pulp was hydrolyzed with cellulase to obtain insoluble and soluble residual lignins. The alkaline effluent from the bleaching was acidified to precipitate alkaline soluble lignin. These lignin preparations were purified, and then analyzed by 2D HMQC NMR spectroscopic techniques. The results showed that biphenyl (5-5) and stilbene structures are preferentially degraded in the bleaching process, while beta-O-4, beta-5, and beta-beta structures undergo degradation only to a lesser extent. This implies that hydrogen peroxide bleaching using the catalyst is more effective in delignification of softwood pulps than hardwood pulps. The possible reaction mechanisms for the delignification of residual lignin in the pine Kraft-AQ pulp in the bleaching process are discussed on the basis of the 2D HMQC NMR spectroscopic data and the model compound experiments.