MICROCHEMICAL JOURNAL
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2023
·
IF 4.8
Chen Yu,Jue Zhang,Xiaogang Luo,Juan Zhang
Based on the excellent physicochemical properties of metal organic framework (MOF) and covalent organic framework (COF), a novel MOF/COF composite was designed and prepared as coating fiber for headspace solid-phase microextraction (HS-SPME). Based on the amino group on the surface of as-synthesized UiO-66-NH 2 , porphyrin-based COF was covalently grown on the MOF surface by using tetra(4-aminophenyl)porphyrin and 4,4′-biphenyldicarboxaldehyde as building blocks to fabricate a novel MOF/COF composite. Subsequently, the composite was physically coated on the surface of polished stainless-steel wire for HS-SPME of polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-flame ionization detection (GC-FID) determination. The morphology and structure of the MOF/COF composite was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and N 2 adsorption–desorption. Influential adsorption and desorption parameters were optimized and the extraction mechanism was also discussed. Under optimal conditions, an HS-SPME/GC-FID method based on MOF/COF composite coated fiber was established for the analysis of PAHs in milk samples. The linear ranges of this method were 0.2–50.0 ng mL −1 (R 2 > 0.9908), and the limits of detection and quantitation were in the range of 0.02–0.07 ng mL −1 and 0.07–0.24 ng mL −1 , respectively. The relative standard deviations (RSDs) for PAHs were all less than 7.05 %, which indicated eminent repeatability and reproducibility of the established method. Besides, the enrichment factors for PAHs were relatively high in the range of 2003 to 7763, and the recoveries for milk samples were ranged from 85.43 % to 115.8 % with satisfactory RSDs of 0.92–9.00 %.
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MICROCHIMICA ACTA
·
2022
·Vol. 189
·期 12
·1-10
·
IF 6.408
Sun Min,Wang Xiuqin,Ding Yali,Feng Juanjuan
In order to improve the selectivity and stability of melamine–formaldehyde (MF) aerogel, it was composited with TiO 2 aerogel. A TiO 2 -MF hybrid aerogel was in situ prepared on the surface of carbon fibers for in-tube solid-phase microextraction (SPME). The extraction performance of TiO 2 -MF aerogel was regulated by changing the ratio of TiO 2 sol and MF sol during the material preparation. Coupled with high-performance liquid chromatography-diode array detection (HPLC–DAD), the extraction tube filled by TiO 2 -MF aerogel-coated carbon fibers was evaluated with several types of environmental pollutants including polycyclic aromatic hydrocarbons (PAHs), estrogens, and ultraviolet filters. Because of favourable extraction performance of PAHs they were selected as model analytes, and some important influence factors were optimized for satisfactory sensitivity. The detection limits were in the range 0.05–0.10 μg L −1 , owing to high enrichment factors (653–1007). The online in-tube SPME-HPLC–DAD method was verified for the determination of trace PAHs in environmental water samples, and acceptable recovery (70–118%) was achieved. The analytical methods also displayed some advantages in comparison with other reports. Moreover, the extraction tube exhibited satisfactory chemical stability. Graphical abstract
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高影响因子
MOLECULES
·
2022
·Vol. 27
·期 21
·7292
·
IF 4.927
Jiangwei Zhang,Fei Yu,Xi Ke,He Yu,Peiyuan Guo,Lei Du,Menglong Zhang,Dongxiang Luo
Conversion of hazardous compounds to value-added chemicals using clean energy possesses massive industrial interest. This applies especially to the hazardous compounds that are frequently released in daily life. In this work, a S-scheme photocatalyst is optimized by rational loading of carbon quantum dots (CQDs) during the synthetic process. As a bridge, the presence of CQDs between TiO2and CdIn2S4improves the electron extraction from TiO2and supports the charge transport in S-scheme. Thanks to this, the TiO2/CQDs/CdIn2S4presents outstanding photoactivity in converting the polycyclic aromatic hydrocarbons (PAHs) released by cigarette to value-added benzaldehyde. The optimized photocatalyst performs 87.79% conversion rate and 72.76% selectivity in 1 h reaction under a simulated solar source, as confirmed by FT-IR and GC-MS. A combination of experiments and theoretical calculations are conducted to demonstrate the role of CQDs in TiO2/CQDs/CdIn2S4toward photocatalysis.Keywords:carbon quantum dots;photocatalysis;degradation;polycyclic aromatic hydrocarbons
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JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Yang Feng,Min Sun,Mingxia Sun,Jiaqing Feng,Haili Sun,Juanjuan Feng
Polyamidoamine dendrimers with different generations (G1-G5) were synthesized in situ on silica progressively via Michael addition and amidation reactions. A sequence of materials was characterized by elemental analysis and Brunauer-Emmett-Teller test, the content of each element (C, H and N) was increased but the surface area was reduced gradually from G1 to G5. These materials were separately packed in a stainless steel column (10 × 4.0 mm, i.d.) for SPE . These SPE columns were combined with high performance liquid chromatography (HPLC) to establish an online SPE-HPLC analysis. According to the chemical structures of materials, polycyclic aromatic hydrocarbons (PAHs) and bisphenols as model analytes were selected to investigate the extraction performance and the extraction mechanism, so as to reveal the extraction performance-structure relationship of G1-G5. The extraction performance was improved with the increase of functional groups from G1 to G4 or G5, the hydrophobic effect played main role accompanied with possible weak hydrophilic, hydrogen-bonding and electrostatic interactions in extraction mechanism. The adsorption capacity, enrichment factor, partition coefficient and extraction efficiency for PAHs and bisphenols reached to 17.52 µg g −1 and 2.70 µg g −1 , 5353 and 3002, 5066 and 1197, and 90.09% and 60.05% respectively. Compared with commercial SPE materials, these dendrimer-grafted silica materials were inferior to C18, but better than silica. Furthermore, the G4 and G5 were separately selected to develop two online SPE-HPLC analytical methods for determining trace PAHs and bisphenols in real water samples, and satisfactory results were obtained.
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MOLECULES
·
2022
·Vol. 27
·期 7
·2353
·
IF 4.927
Yuping Zhang,Ning Wang,Zhenyu Lu,Na Chen,Chengxing Cui,Xinxin Chen
Evaluation of the hydrophobic/hydrophilic interaction individually between the sorbent and target compounds in sample pretreatment is a big challenge. Herein, a smart titanium substrate with switchable surface wettability was fabricated and selected as the sorbent for the solution. The titanium wires and meshes were fabricated by simple hydrothermal etching and chemical modification so as to construct the superhydrophilic and superhydrophobic surfaces. The micro/nano hierarchical structures of the formed TiO2nanoparticles in situ on the surface of Ti substrates exhibited the switchable surface wettability. After UV irradiation for about 15.5 h, the superhydrophobic substrates became superhydrophilic. The morphologies and element composition of the wires were observed by SEM, EDS, and XRD, and their surface wettabilities were measured using the Ti mesh by contact angle goniometer. The pristine hydrophilic wire, the resulting superhydrophilic wire, superhydrophobic wire, and the UV-irradiated superhydrophilic wire were filled into a stainless tube as the sorbent instead of the sample loop of a six-port valve for on-line in-tube solid-phase microextraction. When employed in conjunction with HPLC, four kinds of wires were comparatively applied to extract six estrogens in water samples. The optimal conditions for the preconcentration and separation of target compounds were obtained with a sample volume of 60 mL, an injection rate of 2 mL/min, a desorption time of 2 min, and a mobile phase of acetonile/water (47/53,v/v). The results showed that both the superhydrophilic wire and UV-irradiated wire had the highest extraction efficiency for the polar compounds of estrogens with the enrichment factors in the range of 20–177, while the superhydrophobic wire exhibited the highest extraction efficiency for the non-polar compounds of five polycyclic aromatic hydrocarbons (PAHs). They demonstrated that extraction efficiency was mainly dependent on the surface wettability of the sorbent and the polarity of the target compounds, which was in accordance with the molecular theory of like dissolves like.Keywords:titanium wire;superhydrophobic;superhydrophilic;in-tube solid-phase microextraction;high-performance liquid chromatography
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高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 10
·1766
·
IF 5.719
Qiong Jiang,Shuwu Zhang,Juanjuan Feng,Min Sun
To improve the extraction performance of the silica aerogel, a melamine-terephthalaldehyde polymer was used to hybridize silica aerogel, and the hybridized aerogel was coated on the surface of stainless steel wire to prepare a fiber-filled extraction tube through placing four wires into a polyetheretherketone tube. The tube was combined with high-performance liquid chromatography, then the online extraction and detection were established. Several polycyclic aromatic hydrocarbons (PAHs) were selected as the target analytes. Under the optimum extraction and desorption conditions, the limit of detection was as low as 3.0 ng L−1, and the linear range was 0.01–20.0 μg L−1. The enrichment factors of PAHs were in the range of 1724–2393. Three environmental water samples of mineral water, tap water and river water were analyzed by this method, and the recoveries that spiked at 1.0–10.0 μg L−1were between 80.5–126%. It showed many advantages compared with other methods, such as better sensitivity, faster detection and online analysis.Keywords:solid-phase microextraction;silica aerogel;melamine-terephthalaldehyde polymer;polycyclic aromatic hydrocarbons;online analysis
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Arabian Journal of Chemistry
·
2021
·
IF 5.165
Qiong Jiang,Juanjuan Feng,Min Sun
Carbon fibers (CFs) were modified with carbon nanoparticles (CNPs) by a facile and fast flame preparation method. CNPs-CFs were observed by scanning electron microscope, and the nano-scaled granular structure on the surface was found. This material was also characterized by Raman microscope and X-ray photoelectron spectroscope. It was placed into a polyetheretherketone tube to get an extraction tube, which was connected with high performance liquid chromatography for online analysis. The tube displayed the effective extraction to several polycyclic aromatic hydrocarbons (PAHs), based on the possible hydrophobic and π stacking mechanism. Under the optimized conditions (60 mL of sample volume, 2.00 mL min −1 of sample rate, 0.5% of methanol in sample, 2.0 min of desorption time), an analytical method towards these PAH targets was established. The low limits of detection (0.001–0.005 μg L −1 ), satisfactory linear ranges (0.003–5.0 μg L −1 , 0.003–10.0 μg L −1 ) and efficient enrichment factors (1012–3164) were presented. The method was applied to detect trace targets in several water samples and satisfactory results were obtained. The method provided some superiorities over other analytical methods, like online test, shorter time and better sensitivity.
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INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2021
·
IF 2.826
Xuan Luo,Xiang-Dong Qing,Xu-Chang Miao,Sen Xiang,Hong-Jun Chen,Xiao-Hua Zhang,Min He
In this study, PM10 samples at four locations of Loudi, China were collected from January 2017 to March 2017 and December 2017 to February 2018 at first. Then, a new analytical strategy of second-order calibration based on the alternating trilinear decomposition (ATLD) coupled with gas chromatography-mass spectrometry (GC-MS) was firstly developed for quantitative analysis of seven polycyclic aromatic hydrocarbons (PAHs) in these samples. This strategy is more sensitive and efficient than traditional chromatography not only, but also it can resolve the problems of baseline drift and peaks overlapping in chromatographic analysis. Without the need for intricate pretreatment process and any derivation reactions, useful qualitative and quantitative information of seven PAHs was quickly extracted from the GC-MS-Sample data array by replacing chemical or physical separation with mathematical separation. In validation samples, the average recoveries of seven PAHs ranged from (96.7 ± 4.8) % to (107.9 ± 4.2) %, and the root-mean-square errors of prediction (RMSEPs) were within the range of 0.03–0.35 μg mL−1. The highest concentrations of individual PAHs in these samples were for phenanthrene (1.34 μg mL−1 in monitoring station), acenaphthylene (0.79 μg mL−1 in municipal government) and chrysene (0.53 μg mL−1 in monitoring station). Identified by component analysis, coal combustion and vehicle exhaust were the most possible sources of Loudi, China. These results demonstrated that the proposed method is characterised as a more precise, simple and promising analytical strategy to identify and quantify PAHs in actual aerosol.
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JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Linfeng Chen,Xike Tian,Yong Li,Chao Yang,Yunjie Huang,Yulun Nie
Simple and rapid sensing of polycyclic aromatic hydrocarbons (PAHs) remains a great technical challenge due to their chemical stability and structural similarity. Here, a simple, sensitive and cost-effective sensing strategy is proposed to detect multiple PAHs by utilizing the inner filter effect (IFE) and a reusable fluorescent sensor array consisting of four polyvinyl alcohol (PVA) composite carbon quantum dots (CDs) film sensors. The CDs/PVA films have a wide and tunable excitation range, which provide sufficient spectral overlap with PAHs and ensure the efficient occurrence of IFE. Under different excitations, the diverse UV absorption capacities of PAHs resulted in diverse spectral responses , enabling a unique chemical fingerprint for each PAH. Upon multivariate pattern recognition analysis, the array rendered high-throughput discrimination and sensitive quantification of 16 priority PAHs with 100% classification accuracy and detection limit as low as 57 nM. Moreover, the rapid and accurate screening of multiple environmental samples were also realized with the results consistent with high-performance liquid chromatography . This IFE-based reusable array is readily prepared, green and feasible, which exhibits great potential in environmental analysis and brings an advanced strategy to high-throughput sensing of more pollutants with similar structures and lack of recognition sites.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 17
·24612-24622
·
IF 4.223
Li Zhansheng,Zhao Hongxia,Li Xintong,Bekele Tadiyose Girma
Environmentally persistent free radicals (EPFRs) are an emerging class of environmental hazardous contaminants that extensively, stably exist in airborne particulate matter and pose harmful effects on human health. However, there was little research about the sources of EPFRs in actual atmospheric conditions. This study reported the occurrence, characteristics, and sources of EPFRs and polycyclic aromatic hydrocarbons (PAHs) in PM 2.5 collected in Dalian, China. The concentrations of PM 2.5 -bound EPFRs ranged from 1.13 × 10 13 to 8.97 × 10 15 spins/m 3 (mean value: 1.14 × 10 15 spins/m 3 ). Carbon-centered radicals and carbon-centered radicals with adjacent oxygen atoms were detected. The concentration of ∑PAHs ranged from 1.09 to 76.24 ng/m 3 , and PAHs with high molecular weight (HMW) were predominant species in PM 2.5 . Correlation of EPFRs with SO 2 , NO 2 , O 3 , and 12 kinds of PAHs indicated that both fuel (coal and biomass) combustion and photoreaction in atmosphere influenced the concentrations of EPFR. The positive matrix factorization (PMF) model results have shown that the primary sources contributed most of the EPFRs and those of secondary sources had a little proportion. Coal combustion (52.4%) was the primary contributor of EPFRs, followed by traffic emission (22.6%), industrial sources (9.6%), and secondary sources (9.2%) during the heating period, whereas industrial emission (39.2%) was the primary contributor, followed by coal combustion (38.1%), vehicular exhaust (23.5%), and secondary sources (9.6%) during the non-heating period. The finding of the present study provides an important evidence for further study on the formation mechanism of EPFRs in actual atmospheric to control the air pollution.
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Mingxia Sun,Juanjuan Feng,Jiaqing Feng,Haili Sun,Yang Feng,Xiangping Ji,Chunying Li,Sen Han,Min Sun
To improve the extraction efficiency of carbon fibers (CFs) toward organic pollutants, TiO 2 nanorod arrays (NARs) were grown in situ on CFs. Subsequently, biochar nanospheres and covalent organic framework nanospheres were separately introduced to functionalize the NARs. A sequence of materials was produced by regulating the reactant concentrations and characterized using a scanning electron microscope, an X-ray photoelectron spectrometer, an X-ray diffractometer, a Raman spectrometer, and a specific surface area analyzer. The materials were then deposited into separate poly(etheretherketone) tubes for in-tube solid-phase microextraction (IT-SPME). These tubes were evaluated with different types of organic pollutants (polycyclic aromatic hydrocarbons (PAHs), estrogens, bisphenols, and phthalate esters) using a combination of high-performance liquid chromatography and IT-SPME, and they exhibited diverse extraction performance. The extraction mechanism of each material is carefully discussed, and the structure–performance relationship is also summarized based on the chemical structures and extraction properties of the materials. The most efficient extraction materials for different analytes were discovered and used to develop analytical methods. Three online methods were used to sensitively detect PAHs, estrogens, and bisphenols in real water samples, respectively. Satisfactory results were obtained, including enrichment factors up to 6784, detection limits as low as 0.001 μg L −1 , linear ranges of 0.003–15.0 μg L −1 , and relative standard deviations ranging from 0.2% to 15.2%. The results indicate that these methods have some advantages over previous material-based methods.
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MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Chen Yu,Fengshou Wu,Xiaogang Luo,Juan Zhang
A porphyrin-based covalent organic framework (COF) was synthesized via a Schiff base reaction between tetra (4-aminophenyl) porphyrin and 4,4′-biphenyldicarboxaldehyde. The porphyrin-based COF was physically coated on stainless steel for headspace solid-phase microextraction (HS-SPME) of polycyclic aromatic hydrocarbons (PAHs) prior to their determination by gas chromatography-flame ionization detection (GC-FID). Some properties of the prepared fiber like morphology, structure and stability were tested. The effective parameters including extraction temperature, extraction time, NaCl concentration, agitation speed, desorption temperature and desorption time on the performance by HS-SPME were optimized systematically. The study of extraction mechanism revealed the π-π stacking interaction between porphyrin-based COF fiber and PAHs. Under optimum condition of the developed method, a wide linear range (1–150 ng mL −1 ) with high determination coefficient (R 2 > 0.99), low detection limit (0.25 ng mL −1 ) and low quantitation limit (0.5 ng mL −1 ) were obtained. The repeatability (one fiber, n = 3) and the reproducibility (fiber-to-fiber, n = 3) expressed as the relative standard deviations (RSDs) were in the range of 0.27%–1.75% (intra-day), 2.73%–6.69% (inter-day) and 3.34%–8.62% (fiber-to-fiber), respectively. The developed porphyrin-based COF HS-SPME method had been applied for the determination of PAHs in water and soil samples with satisfactory recoveries in the range of 67.87%–98.74%, 41.13%–104.76%, respectively.
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