JOURNAL OF SEPARATION SCIENCE
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2015
·Vol. 38
·期 16
·2880-2886
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IF 2.737
Xi Zhang,Xiaohuan Zang,Guijiang Zhang,Chun Wang,Zhi Wang
A mesoporous carbon was fabricated using MCM-41 as a template and sucrose as a carbon source. The carbon material was coated on stainless-steel wires by using the sol–gel technique. The prepared solid-phase microextraction fiber was used for the extraction of five volatile aromatic compounds (chlorobenzene, ethylbenzene, o -xylene, bromobenzene, and 4-chlorotoluene) from tea beverage samples (red tea and green tea) prior to gas chromatography with mass spectrometric detection. The main experimental parameters affecting the extraction of the volatile aromatic compounds by the fiber, including the extraction time, sample volume, extraction temperature, salt addition, and desorption conditions, were investigated. The linearity was observed in the range from 0.1 to 10.0 μg/L with the correlation coefficients ( r ) ranging from 0.9923 to 0.9982 and the limits of detection were less than 10.0 ng/L. The recoveries of the volatile aromatic compounds by the method from tea beverage samples at spiking levels of 1.0 and 10.0 μg/L ranged from 73.1 to 99.1%.
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PROGRESS IN ORGANIC COATINGS
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2015
·
IF 2.358
Xuying Nan,Yi Huang,Qinguo Fan,Jianzhong Shao
Dye-linked initiators consisting of erythrosine B as a chromophore and ethyl 4-dimethylaminobenzoate as an electron donor linked by a different number of methylene units were prepared to achieve efficient photoinitiators of free radical polymerization in a visible-light region. The relative photoinitiating efficiencies of novel photoinitiators in photopolymerization of acrylates were evaluated. The results showed that the photoinitiating system composed of the dye-linked dyad with short methylene unit chain and diphenyliodonium salt exhibited a remarkable increase in the photoinitiation ability compared to unlinked three-component system. The enhancement mechanism aroused by the onium salt was investigated. These results showed that the excellent initiating efficiency of this system could be attributed to the favorable intramolecular photoinduced electron transfer and the close distance between reaction components caused by electrostatic interactions. This result demonstrated the importance and potential of the linked photoinitiator in the design of new efficient photoinitiators.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Ziyi Wang,Changyan Guo,Kefu Wang,Jiang Li,Jide Wang
Upgrading waste PET to prepare metal–organic frameworks (MOF) through chemical recycling provides new ideas and methods for PET recycling treatment and high value-added conversion. In this paper, Cobalt-based metal–organic frameworks (Co-MOF) were prepared from PET by one-pot solvothermal method without adding acids or bases. The prepared Co-MOF was used as a heterogeneous catalyst to catalyze the selective oxidation of ethylbenzene (EB) for the preparation of acetophenone (AP). When only tert-butyl hydroperoxide (TBHP) was used as the oxidizing agent without any additional solvents, 89% EB conversion and 94% AP selectivity were achieved, respectively. Moreover, the catalyst showed excellent stability with no significant deactivation under 5 cycles. In addition, the synthesized Co-MOF-10 also exhibits impressive conversion rates of 96% and 93% in benzyl alcohol and styrene oxidation, respectively. Compared with the Co-MOF prepared by commercial terephthalic acid (BDC), the Co-MOF-10 synthesized via the one-pot method using PET exhibits enhanced cost-effectiveness, environmental sustainability, and superior catalytic performance. The present study establishes a foundation for the conversion of plastic PET into valuable MOF and its subsequent application in C–H bond oxidation.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Wei Chen,Xinxin Liao,Feng Chen,Xiang Xia,Ping Tong,Yanqiao Jin,Lei Xiong
Considering the facts of fossil fuel depletion and environmental issues, the conversion of biomass into high value-added chemicals is of great importance. In this work, Ni and Co were encapsulated in lignin-derived phenolic resin spheres to obtain NiCo@LRS, which was then employed as a sacrificial template for the synthesis of the bimetallic catalyst NiCo@LC-RS. The Ni and Co act as the acid and dehydrogenation sites for the catalytic transfer hydrogenolysis of 2-phenoxy-1-phenylethanol ( pp-ol ) and corncob lignin, respectively, and exhibit a synergistic enhancement effect. Under the optimal conditions of 170 °C, 1 MPa N 2 and 4 h, the conversion of pp-ol reached 99.9 %, with the yields of cyclohexanol and ethylbenzene at 99.9 % and 93.8 %, respectively. The lignin was completely converted and the selectivity of monophenols was 55.74 %. The catalyst remained stable and reusable after 5 cycles. Furthermore, lignin oil can be employed in the preparation of Ni Co bimetallic catalysts, which have been demonstrated to exhibit excellent catalytic properties. This work provides practical guidance for the high-value utilisation of lignin.
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TALANTA
·
2025
·
IF 6.1
Zitao Shen,Zhuo Wang,Pengfei Ye,Lihong Guo,Sheng Peng,Yuefan Liu,Yongsheng Cui,Juan Zheng,Gangfeng Ouyang
Macrocyclic polymer materials exhibit excellent selectivity and adsorption performance in pollutant adsorption due to unique host-guest recognition. Herein, three kinds of calixarene polymers (C4P, C6P and C8P) were synthesized through Sonogashira reaction, and were characterized through 1 H NMR, FT-IR, SEM, and TEM. The water contact angle experiments revealed that three kinds of calixarene polymers were highly hydrophobic, and they all exhibited high enrichment efficiency for weak polar chloro-substituted benzene compounds (chlorobenzene, o -chlorotoluene, p-dichlorobenzene and o-dichlorobenzene) and BTEX (benzene, toluene, ethylbenzene and xylenes). Surprisingly, three types of calixarene polymers also showed satisfactory enrichment performance for polar nitrobenzene compounds (NBCs). Among them, C8P showed the most outstanding enrichment factors for NBCs (825-1913), which was about 2–7 times better than those of the commercial fibers. Using C8P as coating fiber, a sensitive analytical method was further developed based on solid phase microextraction (SPME), coupled with gas chromatography-mass spectrometry (GC-MS). The established analytical method demonstrated low detection limits (0.06–5.08 ng L −1 ), a wide linear range (0.5–1000 ng L −1 ), and good repeatability. The established method was further applied to the quantification of NBCs in environmental water samples, verifying its feasibility.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yang Liu,Jian Li,Jiawei Liu,Changwei Tang,Quan Bai
Metal-organic frameworks (MOFs) are promising packing materials in liquid chromatography, but their micropore character extremely prevents the separation performance. Herein, we proposed an acidic etching strategy to fabricate a hierarchically porous University of Oslo-66 (HP-UiO-66) coated silica shell-core composite by using phosphoric acid as an etchant. The prepared composite, namely HP-UiO-66@silica-PA, was characterized by SEM, TEM, FT-IR, and N 2 -adsorption–desorption isotherms, demonstrating the generation of mesopores in HP-UiO-66 shell with pore width ranging in 4–5 nm. The chromatographic performance of HP-UiO-66@silica-PA-1 (etched by 1 mL phosphoric acid for 2 h) as HPLC stationary phase was evaluated in reversed-phase mode, and the separations of three groups of small solutes were studied and compared with the microporous UiO-66@silica (MP-UiO-66@silica) column. The results proved the obviously improved performances with narrower peak width, better resolution, and higher symmetry were achieved by the HP-UiO-66@silica-PA-1 column. The faster diffusion and mass transfer kinetics in the HP-UiO-66 shell signally reduce the plate height and improve the column efficiency. Specifically, the plate number of o -xylene was 18,442 plates m −1 , which was about 18.5 times higher than that on the MP-UiO-66@silica column (993 plates m −1 ). Furthermore, good repeatability and reproducibility with RSDs of both retention time and peak area less than 0.5 % confirmed the high stability and outstanding reliability of the HP-UiO-66@silica-PA-1 column. This study demonstrates that the phosphoric acid etching strategy is simple, mild, and controllable to fabricate hierarchically porous MOFs-based stationary phase for enhancing the HPLC separation performance.
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FUEL
·
2024
·
IF 6.7
Runtian Xia,Naixin Wang,Xinheng Cai,Jing Yang,Hongyu Liu,Zelong Liu,Haomiao Liu,Qundan Zhang,Zhiping Tao,Wei Wang
Advances in ultra-high resolution mass spectrometry and soft ionization technologies have significantly improved the comprehension of complex organic mixtures (COMs) at the molecular level. Atmospheric pressure photoionization (APPI) is a widely used soft ionization source, but the impact of solvents on detected class distribution and double bond equivalent (DBE) range of COMs has been rarely discussed. Herein, the solvent impact of toluene (TOL), m-xylene (MX), ethylbenzene (EB), cyclohexane (CYH), decalin (DHN), and tetralin (THN) on the characterization of three different COMs were studied by APPI Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The numbers of heteroatom compounds detected in THN significantly surpassed those of heteroatom compounds in TOL. Specifically, the analysis results of three COM samples using THN detected 937, 971, and 530 more heteroatom molecules than using TOL. Moreover, the heteroatom compounds detected in THN (N 1 , N 1 O 1 , O 1 S 1 , etc.) showed a much wider DBE distribution, thereby resulting in a more comprehensive molecular profile. The finding aims to ionize more compounds and realize the analysis of non-polar aromatic compounds and heteroatomic compounds simultaneously by using APPI.
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Weidong Wang,Jun Shen,Yu Chen,Dezong Zheng,Lin Li
Benzene, toluene, ethylbenzene and styrene released from furniture and interior decoration materials are important chemicals affecting indoor air quality and have been shown to be harmful to human health. However, little attention is paid for VVOC and their health risks. To close this gap, in April 2022, a 15-L environmental chamber, combined with multibed tube, was used for gas sampling at the Northeast Forestry University laboratory. Emissions of VOC and VVOC from MDF coated with different lacquers were investigated using thermal desorption coupled with gas chromatography-mass spectrometry. The results showed that the total concentrations of VOC and VVOC increased by 37.33%, 96.88%, and 86.45%, respectively, after MDF was coated with water-based (WB), polyurethane (PU), and nitrocellulose (NC) lacquers. The total VVOC concentration from MDF was higher than the total VOC concentration. Alcohols were the most abundant chemicals in MDF, followed by aromatics and alkanes, together accounting for more than 70% of the total. Aromatics and alkanes were the most important VOC after painting. These three lacquers inhibited some VVOC but promoted other chemicals, like benzene, toluene, ethylbenzene and tetrahydrofuran . For health impacts, the cancer risk and noncancer risk of benzene from lacquered MDF were estimated to be 4.46 × 10 −5 to 6.42 × 10 −5 and 0.19 to 0.27 respectively, indicating a probable cancer risk and no obvious noncancer risk. WB-MDF is recommended for indoor applications. This research points the need for exploring environmentally friendly solvents to replace benzene, toluene and ethylbenzene in order to reduce emissions of volatile pollutants.
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Scientific Reports
·
2024
·Vol. 14
·期 1
·1-11
·
IF 3.8
Chu Yajing,Ge Dianlong,Zhou Jijuan,Liu Yue,Zheng Xiangxue,Liu Wenting,Ke Li,Lu Yan,Chu Yannan
Characteristic volatile organic compounds (VOCs) are anticipated to be used for the identification of lung cancer cells. However, to date, consistent biomarkers of VOCs in lung cancer cells have not been obtained through direct comparison between cancer and healthy groups. In this study, we regulated the glycolysis, a common metabolic process in cancer cells, and employed solid phase microextraction gas chromatography mass spectrometry (SPME–GC–MS) combined with untargeted analysis to identify the characteristic VOCs shared by cancer cells. The VOCs released by three types of lung cancer cells (A549, PC-9, NCI-H460) and one normal lung epithelial cell (BEAS-2B) were detected using SPME–GC–MS, both in their resting state and after treatment with glycolysis inhibitors (2-Deoxy- d -glucose, 2-DG/3-Bromopyruvic acid, 3-BrPA). Untargeted analysis methods were employed to compare the VOC profiles between each type of cancer cell and normal cells before and after glycolysis regulation. Our findings revealed that compared to normal cells, the three types of lung cancer cells exhibited three common differential VOCs in their resting state: ethyl propionate, acetoin, and 3-decen-5-one. Furthermore, under glycolysis control, a single common differential VOC—acetoin was identified. Notably, acetoin levels increased by 2.60–3.29-fold in all three lung cancer cell lines upon the application of glycolysis inhibitors while remaining relatively stable in normal cells. To further elucidate the formation mechanism of acetoin, we investigated its production by blocking glutaminolysis. This interdisciplinary approach combining metabolic biochemistry with MS analysis through interventional synthetic VOCs holds great potential for revolutionizing the identification of lung cancer cells and paving the way for novel cytological examination techniques.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Feng Chen,Xuebin Lin,Wei Chen,Na Wen,Yanqiao Jin
The design of a highly active Cu-Co catalyst for catalytic transfer hydrogenolysis of lignin without the use of external hydrogen remains highly challenging. In this work, Cu 2 O was initially encapsulated in ZIF-67, and subsequently Cu 2 O@ZIF-67 was utilized as a precursor and sacrificial template to prepare the unique double core–shell hollow nanocage CuO@Co 3 O 4 . Co and Cu, serving as Lewis acid sites and dehydrogenation sites for the hydrogen-donor solvent isopropanol, respectively, exhibited synergistic enhancement, further increasing the catalytic activity. Under the optimal conditions of 220 °C, 1 MPa N 2 , and 4 h, the catalyst achieved 100 % conversion of 2-phenoxy-1-phenylethanol and 100 % yield towards cyclohexanol and ethylbenzene. Furthermore, the catalyst remained stable and reusable after 5 cycles, providing a practicable guidance for the value-added conversion of lignin.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2024
·Vol. 149
·期 7
·2929-2940
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IF 3
Chen Huanhuan,Fang Chenghui,Zhou Juan,Wu WenQian,Weng Shichun,Chen Liping,Guo Zichao,Chen Wanghua
A rapid increase in viscosity during the polymerization process impacts the polymerization rate. To address this issue, ethylbenzene is often introduced into the polymerization system in order to reduce viscosity. The thermal characteristics of styrene–ethylbenzene polymerization have been identified using differential scanning calorimetry. The rate of heat generation significantly decreases as the proportion of ethylbenzene increases. The polymerization product mixtures were analyzed using gel permeation chromatography. Polymerization at low viscosity yields a higher proportion of low molecular mass polymers and a more uniform distribution of product chain lengths compared to polymerization at high viscosities. The glass transition temperature and the activation energy for viscous flow of the products were also determined. The apparent kinetics of styrene polymerization may be described using the “autocatalytic + Nth-order” model. Two stages of monomer conversion are apparent: polymerization reactions initiated by AIBN and thermally induced polymerization. Valuable insights into the polymerization process which can contribute to the optimization of industrial polymerization reactions have been obtained.
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JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Hu Meng,Yuyu Wei,Liang Feng
In this work, a microchip gas chromatography (GC) column assembly utilizing a three-dimensional (3D) printed micro oven and a flexible stainless steel capillary column was developed. The assembly's performance and separation capabilities were characterized. The key components include a 3D printed aluminum plate (7.50 × 7.50 × 0.16 cm) with a 3-meter-long circular spiral channel, serving as the oven, and the column coiled on the channel with an inner diameter of 320 μm and a stationary phase of OV-1. A heating ceramic plate was affixed on the opposite side of the plate. The assembly weighed 40.3 g. The design allows for easy disassembly, or stacking of heating devices and columns, enabling flexibility in adjusting column length. When using n -C 13 as the test analyte at 140 °C, a retention factor ( k ) was 8.5, and 7797 plates (2599 plates/m) were obtained. The assembly, employing resistance heating, demonstrated effective separation performance for samples containing alkanes, aromatics, alcohols and ketones, with good reproducibility. The reduction in theoretical plates compared to oven heating was only 2.95 %. In the boiling point range of C 6 to C 18 , rapid temperature programming (120 °C/min) was achieved with a power consumption of 119.512 W. The assembly was successfully employed to separate benzene series compounds, gasoline and volatile organic compounds (VOCs), demonstrating excellent separation performance. This innovative design addresses the challenges of the complexity and low repeatability of the fabrication process and the high cost associated with microchip columns. Furthermore, its versatility makes it suitable for outdoor analysis applications.
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