JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Aimin Li,Xiaolan Huang,Ling Yan,Jing Cheng
2,4,6-trihalorophenol disinfection by-products (DBPs) have strong toxicity to be needed for monitoring. In this study, two kind of molecularly imprinted polymeric fibers were prepared using 2,4,6-trichlorophenol as template and tricuronic phloroglucinol (MOP) as pseudo-template, respectively. The two fibers were assembled as solid phase microextraction (SPME) fiber to extract 2,4,6-trihalophenol DBPs from water and detect them by gas chromatography coupled to electron capture detector (GC-ECD). The results of F-test and t-test stated that there are significant difference in the analytical results of 2,4,6-trichlorophenol between using the fiber based on 2, 4, 6-trichlorophenol as template and MOP as pseudo-template. It was found that the carry-over of template (2,4,6-trichlorophenol) leaked from the fiber in GC thermal desorption, resulting in the wrong quantitative analytical result for 2,4,6-trichlorophenol in water. Hence, molecularly imprinted polymeric fibers based on MOP as pseudo-template was applied for the determination of 2,4,6-trihalophenol DBPs in water combined with GC-ECD. The selectivity of the fiber for 2,4,6-trihalophenol DBPs was investigated and demonstrated. Under the optimized condition, the method has much lower limit of detection (0.5–1.1 pg mL −1 ) than most reported methods. The method was applied for the determination of 2,4,6-trihalophenol DBPs in environmental water and the relative recoveries were found to be in the range from 77.1% to 105.6% and the relative standard deviation was 0.5–9.4%. 2,4,6-tribromophenol was found at concentration of 0.054 ng mL −1 in a swimming pool.
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FOOD CHEMISTRY
·
2022
·
IF 9.231
Yi-Lian Zhou,Shi-Wen Yue,Bing-Wei Cheng,Qin Zhao
In this study, a convenient and economic method for the determination of fipronil and its three metabolites in edible oil was developed based on pollen grain solid-phase extraction (SPE). As a natural material, pollen grains exhibit well absorption capacity for some polar compounds due to their special functional structures. Their stable composition and appropriate particle size also make them suitable for SPE. In the present study, natural pine pollen grains without broken wall were used as sorbent for selective isolation and enrichment of fipronil and its three metabolites from edible oils based on hydrogen bond interaction. Several parameters influencing the extraction recoveries were investigated. By coupling with gas chromatography-electron capture detection (GC-ECD), a new method for analysis of fipronil and its metabolites in edible oils was established. The linearity range was 2–200 ng/g with correlation coefficient R 2 more than 0.999. The recoveries in edible oils at three spiked concentrations were in the range of 80.1–96.0% with the RSDs less than 10.6% (intra-day) and 11.5% (inter-day). The limit of detection (LOD) for four target analytes were in the range of 0.2–0.6 ng/g, which was comparable to the previous reported methods. Finally, the established method was successfully applied to detect fipronil and its metabolites in several oil samples with different brands from local market.
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Journal of Fungi
·
2021
·Vol. 8
·期 1
·10
·
IF 5.816
Dyaaaldin Abdalmegeed,Gan Zhao,Pengfei Cheng,Javaid A. Bhat,Wajid Ali Khattak,Mostafa G. Ali,Fawze Alnadari,Ilyas Ali,Qurban Ali,Sameh A. Korma,Yehia A.-G. Mahmoud,Manar K. Abd Elnabi,Weiti Cui,Wenbiao Shen
Whether or not hydrogen gas (H2) can reduce cadmium (Cd) toxicity inGanoderma lucidumhas remained largely unknown. Here, we report that Cd-induced growth inhibition inG. lucidumwas significantly alleviated by H2fumigation or hydrogen-rich water (HRW), evaluated by lower oxidative damage and Cd accumulation. Moreover, the amelioration effects of H2fumigation were better than of HRW in an optimum concentration of H2under our experimental conditions. Further results showed that H2-alleviated growth inhibition inG. lucidumwas accompanied by increased nitric oxide (NO) level and nitrate reductase (NR) activity under Cd stress. On the other hand, the mitigation effects were reversed after removing endogenous NO with its scavenger cPTIO or inhibiting H2-induced NR activity with sodium tungstate. The role of NO in H2-alleviated growth inhibition under Cd stress was proved to be achieved through a restoration of redox balance, an increase in cysteine and proline contents, and a reduction in Cd accumulation. In summary, these results clearly revealed that NR-dependent NO might be involved in the H2-alleviated Cd toxicity inG. lucidumthrough rebuilding redox homeostasis, increasing cysteine and proline levels, and reducing Cd accumulation. These findings may open a new window for H2application in Cd-stressed economically important fungi.Keywords:hydrogen fumigation;nitric oxide;hydrogen-rich water;stress alleviation;cysteine;proline;Ganoderma lucidum
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NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 17
·7594-7601
·
IF 3.591
Yongrui He,Meiling Qi
This work presents a novel strategy for the construction of a capillary column with high resolving performance and inertness for gas chromatographic (GC) analysis by combining the proposed surface modification with a selective stationary phase. Through the modified biphasic sol–gel reaction inside a capillary GC column, porous modification was made on the capillary surface (PM capillary) prior to coating with a stationary phase. Herein, we designed and synthesized a new triptycene-based stationary phase (TPPG) for the study. Using the proposed strategy, the PM-TPPG column was fabricated with a column efficiency of 4950 plates per m determined by n-dodecane at 120 °C and then investigated for its separation performance, inertness, repeatability, loadability and thermal stability. As demonstrated, the PM-TPPG column showed distinct advantages in these aspects over two reference columns (TPPG column and commercial PEG column). Particularly, the PM-TPPG column well resolved all the components in the Grob mixture and exhibited distinctly improved peak shapes for carboxylic acids and heterocyclic bases. Moreover, it exhibited excellent repeatability and reproducibility and higher column loadability than the two reference columns. Its applications to purity monitoring of chemical products demonstrate its good potential for practical GC analysis.
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SN Applied Sciences
·
2021
·Vol. 3
·期 3
·1-9
·
IF 0
Ma Yinzheng,Wen Yingying,Chen Jinping,Zhang Yunxia,Zhang Haiying,Sui Jinlei,Yi Guohui,He Xiaowen
A rapid and sensitive headspace gas chromatography-mass spectrometry (HS-GC–MS) method was established for the determination of benzyl isothiocyanate (BITC) in the peel, pulp, and seeds of Carica papaya Linn. Tween 80 solution with a concentration of 0.002% ( w/v ) was chosen as a headspace medium for solving the poor solubility of BITC in water without using organic solvents and ensuring high headspace efficiencies. Extraction parameters had been evaluated and optimized by using an orthogonal design with an OA 9 (3 4 ) table. Optimal headspace conditions were obtained when vials were equilibrated at 80 °C for 20 min at a stirring speed of 375 rpm. The calibration curve obtained by using GC–MS was linear in a concentration range of 10–320 ng/mL. The recoveries of peel, pulp, and seeds ranged from 97.3 to 100.6% with RSDs less than 3.0%. The method is simple, rapid, sensitive, and environmentally friendly. It is suitable for analyzing BITC in papaya fruit and is expected to have important application potential in the extraction of water-insoluble volatile components in foods, plants, medicines, and other samples.
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FUEL
·
2021
·
IF 6.609
Ya-Qi Shan,Lin-Xin Yin,Oraléou Sangué Djandja,Zhi-Cong Wang,Pei-Gao Duan
Ru supported on activated carbon (C), Al 2 O 3 , CeO 2 , MgO, TiO 2 , and ZrO 2 were prepared and employed to boost supercritical water gasification (SCWG) of microalgae hydrothermal liquefaction (HTL) downstream water at 600 °C for 1 h. Effects of catalysts, water density, and Ru/C loading on total organic carbon (TOC) reduction, carbon gasification efficiency (CGE), and gas yield were examined. All the Ru catalysts showed a positive effect on TOC reduction and converted organics in the HTL downstream water to fuel gas, with H 2 and CH 4 as the two most abundant component. With the addition of Ru/C, almost complete removal of TOC, the highest CGE, and H 2 yield were achieved due to its largest metal dispersion. With the addition of Ru/C, increasing water density and catalyst loading favored TOC reduction and CGE increase as well as the total gas yield. The highest H 2 content of 50% and yield of 2.62 mmol/g (aq.) were obtained at the highest catalyst loading of 12.0 mg (Ru/C) /mL (aq.) . This study suggested that SCWG with the addition of Ru/C was a promising strategy to produce fuel gas rich in H 2 , from the organics in the microalgae HTL downstream water.
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JOURNAL OF SEPARATION SCIENCE
·
2020
·Vol. 43
·期 7
·1306-1315
·
IF 2.878
Le Song,Canping Pan,Juan Yang,Sujia Zeng,Yongtao Han
A rapid and effective method was developed for the analysis of 39 pesticide residues in porcine meat with dual-layer multiplug filtration cleanup and gas chromatography-tandem mass spectrometry detection. The cleanup process was performed with columns packed with two layers, namely multiwalled carbon nanotubes, C18 and anhydrous magnesium sulfate (MgSO 4 ) as top layer, while mixture of florisil and MgSO 4 as bottom layer. A single-layer method was tested in parallel, with columns packed with the same amount of absorbents. Extraction conditions and filtration cleanup process were optimized to obtain satisfied method performance. Method linearity was calculated with coefficients of determination more than 0.995. The limits of quantitation were verified with acceptable accuracy at the lowest spiked concentration of 0.01 mg/kg (except pyrimethanil). The recoveries at three fortified levels (0.01, 0.05, and 0.1 mg/kg) in five replicates were between 74 and 118% (except pyrimethanil) with relative standard deviations range from 1 to 16%. The matrix effects were in the range of 1.01 to 2.84. This new method was applied for the analysis of multipesticide residues in market samples of porcine meat. This study showed the dual-layer multiplug filtration cleanup demonstrated better performance than that with the single-layer columns in cleanup of porcine meat.
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POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Chanchal Kumar Kundu,Xin Wang,Mohammad Ziaur Rahman,Lei Song,Yuan Hu
A DOPO-based phosphorus compound (DOPA) was synthesized and applied onto the pure and chitosan (CS) modified polyamide 66 (PA66) fabric surfaces via a simple pad-dry-cure method to improve the flame retardant properties of the same. The pure and chitosan modified fabric samples treated with DOPA at different content % degraded in a different way as the char residue formation and releasing of volatile and non-volatile gas species were dissimilar which were evident from the thermogravimatric and thermogravimetric-gas chromatography-mass spectroscopy (TG-GC-MS) test analysis. Obtained results also showed that no dripping occurred in the vertical burning test and a sharp increase in limiting oxygen index (LOI) values was noticed for all the treated fabric samples. CS modified PA66 fabric sample treated with a 10 wt % of DOPA exhibited a greater reduction in pHRR by 40% and showed superior flame retardant performance compared to the only DOPA treated pure fabric sample. The superb flame retardant properties of CS modified fabrics were due to the co-presence of DOPA and CS; where a synchronized gas phase and a condensed phase flame retardant mechanism was realized as DOPA showed a quenching effect in a gas phase mechanism and simultaneously, catalyzed the charring of CS in a condensed phase activity which was also justified from the TG-GC-MS analysis, TGA and FTIR analysis of char residues. However, this kind of facile application showed poor wash durability and deteriorated the physical properties of the fabric materials specifically treated with a higher DOPA content.
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JOURNAL OF MEMBRANE SCIENCE
·
2020
·
IF 7.183
Zixing Guo,Wenji Zheng,Xiaoming Yan,Yan Dai,Xuehua Ruan,Xiaochen Yang,Xiangcun Li,Ning Zhang,Gaohong He
Cage-type MOFs based Mixed-matrix membranes (MMMs) hardly exhibit screening effect of gas molecules due to the flexible aperture. Regulation of nanocages of MOFs by Ionic Liquid (IL) has been proved to be effective. Therefore, in this work, an IL adsorption/infiltration two-step strategy is proposed to confine IL into the nanocages of MOFs, achieving fine tuning of effective cage size for screening gas pair with similar size. [Bmim][PF 6 ] are first adsorbed on the outer-surface of ZIF-8, then through heat treatment, the aperture of ZIF-8 is dilated, and the bigger [Bmim][PF 6 ] molecules infiltrate through the dilated aperture into the nanocage driven by thermodynamics and differential concentration. When the temperature is down to room temperature, the aperture is narrowed to 3.4 Å, thus [Bmim][PF6] are confined into nanocages, which are confirmed by PXRD , TGA and FT-IR characteristics. By controlling IL content in the cage, the effective cage size of ZIF-8 is tuned to specific slope among dynamic diameters of CO 2 over N 2 , which is perfectly reflected in the CO 2 /N 2 separation. Compared with ZIF-8/Pebax MMMs, the IL@ZIF-8/Pebax MMMs exhibit improved CO 2 /N 2 selectivity but decreased CO 2 permeability, demonstrating effectiveness of cage size adjustment. Furthermore, with the IL molecules inside ZIF-8 cage increasing, the CO 2 /N 2 selectivity of the MMMs continues to rise, indicating cage size screening effect of ZIF-8 by IL infiltration . Especially, the IL 8 @ZIF-8/Pebax MMMs exhibit the best gas separation performances with CO 2 permeability of 117 Barrer and CO 2 /N 2 selectivity of 84.5, beyond the 2008 Robinson upper bound. The proposed strategy provides an effective but facile way to confine IL into the cages of MOFs to precisely screen gas pairs with similar size and can be easily expanded to other IL and MOFs system.
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APPLIED CATALYSIS A-GENERAL
·
2019
·
IF 4.63
Yuhai Sun,Jingjing Li,Peirong Chen,Bangfen Wang,Junliang Wu,Mingli Fu,Limin Chen,Daiqi Ye
Palladium-loaded ZnO (Pd/ZnO) catalyst was synthesized by co-precipitation method and evaluated for plasma-catalytic reverse water-gas shift (RWGS) reaction. A CO 2 conversion of 32.5 % was achieved on “Pd/ZnO + Plasma”, and was around two times higher than that of “ZnO + Plasma” (17.3 %). Catalyst characterization by X-ray diffraction, high-resolution transmission electron microscopy, temperature-programmed reduction and quasi in situ X-ray photoelectron spectroscopy revealed the possible formation of ZnO x @PdZn (ZnO x decorated PdZn alloy) at the interface of Pd active phase and ZnO support. The role of ZnO x @PdZn in plasma-catalytic CO 2 conversion was systematically investigated by plasma-excited CO 2 temperature-programmed desorption and in situ Fourier transform infrared spectroscopy. It was found that ZnO x @PdZn at Pd-ZnO interface improved significantly plasma-catalytic CO 2 conversion by promoting the production of bidentate carbonate and bidentate formate species. In situ Raman spectroscopy studies proved that the ZnO x @PdZn remained largely intact during the RWGS process. Our in situ spectroscopic findings thus unveil that the ZnO x @PdZn at Pd-ZnO interface favors the activation of CO 2 , and, consequently, leads to a higher plasma-catalytic performance for CO 2 conversion.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Bing Liu,Xiaochen Xu,Yuan Xue,Lifen Liu,Fenglin Yang
An integrated method of simultaneous desulfurization and denitrification from flue gas by catalytic ozonation combined with NH 3 /(NH 4 ) 2 S 2 O 8 absorption was developed for the first time. It consisted of two parts: (1) the catalytic ozonation of NO over FeO x /SAPO-34 to study the effects of the various influencing factors, and (2) the absorption–oxidation of NO x and SO 2 induced by ozone combined with a NH 3 /(NH 4 ) 2 S 2 O 8 solution in a bubble column reactor. In Part 1, results showed that under the optimal condition of a molar ratio of 0.5 for O 3 /NO, a residence time of 3 s, a water vapor volume fraction of 4%, a NO initial concentration of 536 mg/m 3 , and a SO 2 initial concentration of 343 mg/m 3 , the oxidation rate of NO was 55%. The characterizations of poisoned catalyst are briefly discussed. In Part 2, as the gas passed sequentially through the ozonizing reactor and the absorber (NH 3 /(NH 4 ) 2 S 2 O 8 solution of 0.8% ammonia and 0.2 mol/L (NH 4 ) 2 S 2 O 8 ), a NO conversion rate of approximately 92.6% and SO 2 conversion rate of 100% were obtained. The pH of the NH 3 /(NH 4 ) 2 S 2 O 8 solution had a significant impact on the NO conversion. According to the analysis of the composition of products under different pHs, a mechanism of desulfurization and denitrification based on NH 3 /(NH 4 ) 2 S 2 O 8 solutions was proposed. The reaction product as a compound fertilizer contained up to 24.5% nitrogen.
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JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
J.L. Wang,Y.J. Guo,G.D. Long,Y.L. Tang,Q.B. Tang,X.T. Zu,J.Y. Ma,B. Du,H. Torun,Y.Q. Fu
Surface acoustic wave (SAW)-based formaldehyde gas sensor using bi-layer nanofilms of bacterial cellulose (BC) and polyethyleneimine (PEI) was developed on an ST-cut quartz substrate using sol-gel and spin coating processes. BC nanofilms significantly improve the sensitivity of PEI films to formaldehyde gas, and reduces response and recovery times. The BC films have superfine filamentary and fibrous network structures, which provide a large number of attachment sites for the PEI particles. Measurement results obtained using in situ diffuse reflectance Fourier transform infrared spectroscopy showed that the primary amino groups of PEI strongly adsorb formaldehyde molecules through nucleophilic reactions, thus resulting in a negative frequency shift of the SAW sensor due to the mass loading effect. In addition, experimental results showed that the frequency shifts of the SAW devices are determined by thickness of PEI film, concentration of formaldehyde and relative humidity. The PEI/BC sensor coated with three layers of PEI as the sensing layer showed the optimal sensing performance, which had a frequency shift of 35.6 kHz for 10 ppm formaldehyde gas, measured at room temperature and 30 % RH. The sensor also showed good selectivity and stability, with a low limit of detection down to 100 ppb.
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危险品化学品经营许可证（带存储）