JOURNAL OF CHEMICAL THERMODYNAMICS
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2022
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IF 3.269
Jinkun Guo,Bo Jin,Shijin Chu,Rufang Peng
A different type of heat-flow calorimeter is developed to measure the energy of combustion. This calorimeter uses differential thermopile as the heat-flow sensor. The calorimeter and oxygen bomb have a special structure to ensure that the heat generated by combustion heat is slowly transferred to the thermopile, and the temperature of the outside interface of the thermopile is constant. The calorific coefficient is determined by chemical calibration, providing for the chemical calibration S =(64.806 ± 0.029) μV mW −1 , which means uncertainty is 0.05 % for calibration. The combustion enthalpies of anthracene and naphthalene are measured by using this calorimeter, and the results agree with the literature values or recommended values.
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MICROCHEMICAL JOURNAL
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2022
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IF 5.304
Yuan Peng,Si-Yuan He,Fang-Huan Wang,Hao-Bo Zheng,Zhe Meng
In this work, a magnetic mesoporous molybdenum disulfide/graphite nanosheets (mm-MoS 2 /GN) was successfully synthesized and applied to magnetic solid phase extraction (MSPE) of 13 polycyclic aromatic hydrocarbons (PAHs) from edible oil samples. The prepared mm-MoS 2 /GN was characterized by FT-IR, XRD, VSM, BET, SEM and TEM. The influence of various parameters such as the adsorbent mass, adsorption/desorption time, and elution solvent through response surface methodology in MSPE was investigated. The porous and fluffy structure with rich active sites (π interactions, electrostatics, hydrogen bonds) and amphiphilicity properties of mm-MoS 2 /GN make it an ideal material for the separation and enrichment of trace PAHs in edible oils. Under optimal MSPE and GC-MS conditions, the linearity ranges of the proposed method were 1.0–100.0 μg·kg −1 with a satisfactory correlation coefficient above 0.9907. The limits of detection and quantification for 13 PAHs were 0.10–2.50 μg·kg −1 and 0.85–5.00 μg·kg −1 , respectively. The intra- and inter-day precisions were less than 3.0 % and 3.6 %, respectively. The recoveries for spiked edible oil samples ranged from 70.2 % to 112.6 % with RSDs of less than 5.8 %. In this work, a novel, rapid, economic and effective method was proposed, and successfully applied to detect polycyclic aromatic hydrocarbons in several oil samples from local market.
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Nanomaterials
·
2022
·Vol. 12
·期 17
·2921
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IF 5.719
Yu Tian,Zhigang Xu,Zhimin Liu,Xiaoxi Si,Fengmei Zhang,Wei Jiang
In the present study, silica-coated magnetic nanoparticles functionalized with vancomycin (Fe3O4@SiO2@VAN) were synthesized. The Fe3O4@SiO2@VAN nanocomposite was used as a sorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from environmental water, followed by GC-MS. The nanocomposite was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and nitrogen sorption. Various experimental parameters were optimized, including extraction condition and desorption condition. Results show that Fe3O4@SiO2@VAN combined the advantages of nanomaterials and magnetic separation technology, showing excellent dispersibility and high selectivity for PAHs in environmental water sample. Under the optimal extraction conditions, an analytical method was established with the sensitive limit of detection (LOD) of 0.03–0.16 μg L−1. The method was successfully applied for the analysis of environmental water samples. The relative standard deviations (%) were in the range of 0.50–12.82%, and the extraction recovery (%) was in the range of 82.48% and 116.32%. MSPE-coupled gas chromatography–mass spectrometry quantification of PAHs is an accurate and repeatable method for the monitoring of PAH accumulation in environmental water samples. It also provides an effective strategy for the tracing and quantification of other environmental pollutants in complex samples.Keywords:magnetic solid-phase extraction;polycyclic aromatic hydrocarbons;vancomycin;GC-MS
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ENVIRONMENTAL RESEARCH
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2022
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IF 8.431
Lingyu Wen,Yiqun Huang,Weiwei Wang,Lige Zhang,Jijun Xu,Zhao Li,Ping Xu,Hongzhi Tang
Polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene , are a type of organic pollutants that exist widely in the environment. Of the currently known degradation methods, bioremediation is a desirable and feasible option. A novel Diaphorobacter sp. Strain MNS-0 was isolated from saponification wastewater and showed the ability to degrade phenanthrene, fluorene, acenaphthene, anthracene , benzo[ a ]anthracene, or chrysene using phenanthrene as the sole carbon source. Gas chromatography mass spectroscopy analysis of catabolic intermediates indicates that phenanthrene degradation occurs through the phthalic acid pathway in strain MNS-0. Genome sequencing shows that strain MNS-0 has two plasmids and one chromosome containing a presumptive phenanthrene degradation gene cluster. Strain MNS-0 was able to completely degrade 100 mg/L phenanthrene within 40 h and tolerate up to 10 g/L NaCl at pH 9.0, while maintaining phenanthrene degradation activity. We thus propose that strain MNS-0 is an effective degrader for bioremediation of PAHs pollution, even in relatively harsh alkali environments such as saponification wastewater.
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FOOD CHEMISTRY
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2022
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IF 9.231
Chengcheng Zhai,Mingwei Wang,Yanke Lu,Hongyuan Yan
Polycyclic aromatic hydrocarbons (PAHs) posed a serious threat to food safety and human health due to long-term emission. In this work, a new method was established using phloroglucinol-urotropine porous polymer (PU-PP) in a pipette tip for solid phase extraction (PT-SPE) for the first time and used prior to determination of four PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) in lotus roots. Synthesis of the PU-PP adsorbent was green compared with alternatives; urotropine was used as a cross-linker and ethanol–water as the solvent. PU-PP-based PT-SPE had the advantages of low solvent consumption, good purification, practicability, stability, and low-cost. The proposed pre-purification method offered low limits of detection (0.09–0.28 ng/g) and good recoveries (84.6–114.3 %, RSDs ≤ 5.6 %) for determination of the four PAHs, which were detected at trace concentrations in samples. This new method provides an alternative for monitoring trace pollutants in aquatic plant ingredients.
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JOURNAL OF CHROMATOGRAPHY A
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2022
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IF 4.601
Yanyan Wang,Lili Lian,Xiyue Wang,Boying Yue,Lan Ding,Dawei Lou
In this study, velvet-like carbon nitride (V-g-C 3 N 4 ) was prepared from urea aqueous solutions by one-step thermal polycondensation. The V-g-C 3 N 4 material was then characterized using a scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FT-IR), and nitrogen adsorption-desorption isotherms. The specific surface area of V-g-C 3 N 4 (60.66 m 2 /g) was 1.8 times that of the carbon nitride (g-C 3 N 4 ) prepared by the traditional method. V-g-C 3 N 4 was modified on the surface of stainless-steel wire by a sol-gel technique to obtain a solid-phase microextraction (SPME) coating for the extraction of five polycyclic aromatic hydrocarbons (PAHs) from water samples. The chromatography signal of the PAHs extracted using the V-g-C 3 N 4 coating was 1.5 times that when using a g-C 3 N 4 coating, and 5–10 times that when using commercial PDMS. Under the optimized extraction conditions, the linear range of the method developed for the determination of five PAHs was 0.05–100 µg/L, the limits of detection were 0.005–0.012 µg/L, and the recoveries from actual water samples were 85.94–103.47%. Furthermore, the developed SPME device is remarkably durable and can be reused up to 160 times.
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Nanophotonics
·
2022
·Vol. 11
·期 12
·2875-2889
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IF 7.923
Mengya Zhang,Yue Tian,Anxin Jiao,Hui Ma,Chang Wang,Linqi Zheng,Shuang Li,Ming Chen
Ultrasensitive trace-detection of toxic and carcinogenic polycyclic aromatic hydrocarbons (PAHs) can ceaselessly propel the environmental surveillance in aqueous ecosystems. Due to the intrinsic nonadsorptive feature of PAHs, the promising technique of surface-enhanced Raman scattering (SERS) spectroscopy has been restricted to diverse functional ligands-based surface modifications of nano-substrates. However, it is not suitable for practical ultralow liquid analysis. Herein, we propose an extraordinary strategy to boost liquid-near infrared (NIR)-SERS activity of plasmonic Au/Ag nano-urchins (NUs) by introducing extra 808 nm laser-triggered an additional strong electromagnetic enhancement into routine 785 nm laser-Raman system. The synergistic double laser-excited NIR-SERS of colloidal Au/Ag NUs enables the Raman signals of crystal violet to be significantly enhanced, approaching a maximum of ∼34-fold increase than that of traditional bare 785 nm laser-excitation. More importantly, the improved liquid-NIR-SERS enables the in-situ detection limit of pyrene molecules in lake water to be achieved at ∼10 −9 M, which is already better than many previous SERS results based on the complicated functionalized nano-substrates. The established double laser-boosted NIR-SERS can also be easily extended to the simultaneous trace-detection of three PAHs-contaminated mixtures, supporting well distinguishable capability. Undoubtedly, the present work opens a new versatile and innovative avenue for ultrasensitive NIR-SERS monitoring of nonadsorptive toxic pollutants in wastewater.
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MOLECULES
·
2022
·Vol. 27
·期 7
·2353
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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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JOURNAL OF CHROMATOGRAPHY A
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2022
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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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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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JOURNAL OF SEPARATION SCIENCE
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2022
·Vol. 45
·期 9
·1493-1501
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IF 3.614
Chengjiang Zhang,Hongmei Yuan,Zeyi Lu,Yuhuang Li,Lirong Zhao,Zhuomin Zhang,Gongke Li
Covalent organic frameworks with tunable porous crystallinity and outstanding stability have exhibited fascinating pretreatment performance as ideal extraction media. Herein, the β-ketoenamine-linked TpPa-1 synthesized by 1,3,5-triformylphloroglucinol and paraphenylenediamine was employed as the absorbent for online micro-solid phase extraction of trace bisphenols combined with high-performance liquid chromatography detection. A series of characterizations indicated that the TpPa-1 possessed large surface areas, high stability, and hydrophobicity. The main experimental parameters affecting the extraction efficiency were optimized in detail. Compared with four commercial sorbents, the TpPa-1 exhibited superior enrichment capacity for extracting bisphenols. Under the optimum conditions, the established method demonstrated a wide linear range and high sensitivity with the limit of detection ranging from 0.05–0.06 μg/L. Furthermore, the developed method was successfully applied to determine bisphenols in plastic samples. Bisphenol A was actually detected in a transparent box with a concentration of 0.31 μg/g, and the recoveries of the four bisphenols in the plastic samples were 80.5–116% with the relative standard deviation less than 9.2%. Such performance was attributed to recognition affinity, including the π-π affinity, hydrophobic effect, and hydrogen bond. These results demonstrated that TpPa-1 possessed great potential to be an excellent pretreatment medium for online separation and analysis of trace analytes in complex samples.
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ENERGY & FUELS
·
2022
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IF 4.654
Xiuhong Zhang,Dong Wang,Xiao Chen,Longwei Meng,Changhai Liang
The hydrogenation of polycyclic aromatic hydrocarbons (PAHs) over highly efficient and stable catalysts to fine chemicals and intermediates for producing chemical materials is an effective approach to realize the high value-added utilization of coal tar and slurry oil. Herein, two kinds of Al2O3-supported Pt and Rh catalysts are synthesized by strong electrostatic adsorption (SEA) and used to catalyze the hydrogenation of anthracene. Compared with the traditional catalysts synthesized by wet impregnation, the Pt/Al2O3-SEA and Rh/Al2O3-SEA catalysts have smaller active metal particle sizes and higher dispersion, which can expose more active centers, showing higher catalytic activity. Interestingly, anthracene may be preferentially adsorbed on the surface of the Pt/Al2O3 catalyst in a parallel manner but on the surface of the Rh/Al2O3 catalyst in a lateral manner, which leads to the different hydrogenation routes. 9,10-Dihydroanthracene is an initial product for the hydrogenation of anthracene, which is rearranged into tetrahydroanthracene and subsequently hydrogenated to symmetrical octahydroanthracene (sym-OHA) over the Pt/Al2O3 catalyst. The high selectivity to sym-OHA (93%) with the conversion of anthracene near 100% can be achieved in the hydrogenation of anthracene at 240 °C and 7 MPa for 10 h. Additionally, due to the strong anchoring effect, the Pt/Al2O3-SEA catalyst shows high stability for six cycles. This work supplies a new tactic to develop high-performance catalysts for selective hydrogenation of PAHs to important monomers for synthesizing chemical materials.
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