Water
·
2022
·Vol. 14
·期 15
·2371
·
IF 3.53
Huili Tang,Ziru Li,Hanqing Chen,Yang Xu,Xu Jiang,Erdeng Du,Zhen Lyu,Lu Zheng,Mingguo Peng
N-nitrosamines have recently attracted attention as a class of disinfection byproducts and are also a hot spot in environmental studies. Current N-nitrosamine analytical methods typically involve manual solid phase extraction (SPE) of samples followed by quantitative analysis using liquid chromatography-mass spectrometry (LCMS), which is time-consuming and may also fail to eliminate complex matrix effects. Size exclusion chromatography (SEC) is a technique that can separate compounds according to their molecular size. For the first time, this study developed an Online-SPE/SEC/LCMS quantitative analysis method to detect and analyze nine common N-nitrosamine disinfection byproducts in wastewater plant tailwater, including N-dimethylnitrosamine (NDMA) and N-nitrosodiethylamine (NDEA), etc. The samples of 1.0 mL can be directly injected after the simple 0.22 μm membrane filtration. This method reports the combination of SPE, SEC, and RP C18 columns to achieve several functions in a processing time of 20 min, including online enrichment, desalination, and matrix separation for the first time. The method provides good linearity (R2> 0.999), recoveries ranging from 91.67% to 105.88%, relative standard deviation (RSD) lower than 4.17%, and the limits of detection (LOD) are 0.12–6.60 ng/L. This method alleviates tedious human labor and can effectively overcome the matrix effect (ME< 20%). This method allows for the accurate quantitative analysis of N-nitrosamines with high compatibility in wastewater plant tailwater, rivers, and lakes with a high background matrix. Interested researchers can also use this method as a reference in the online analysis of other specific pollutants after necessary optimization. It can also be utilized for non-targeted screening and targeted analysis of contaminants in water with a wide range of applications, giving valuable information for environmental monitoring.Keywords:N-nitrosamines;analysis method;online solid-phase extraction (Online-SPE);size exclusion chromatography (SEC);LCMS;column switching;wastewater plant tailwater
研究领域:
环境科学
·
分析化学
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DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 6
·767
·
IF 4.7
Changhai Zhang,Ziyang Liu,Chao Tang,Tiandong Zhang,Yue Zhang,Yongquan Zhang,Qingguo Chi
With the policy tilt and increased investment in research and development in the world, new energy vehicle technology continues to progress and the drive motor power density continues to improve, which puts forward higher requirements for the comprehensive performance of the core insulating material enameled wire enamel for drive motors. Polyimide (PI) has excellent electrical insulation properties, and heat resistance is often used to drive the motor winding insulation. To further improve the corona resistance and insulating properties of PI wire enamel varnish, in this paper, firstly, fluorene groups with a rigid conjugated structure were introduced into the molecular chain of the PI film by molecular structure modulation, and then uniformly dispersed alumina nanoclusters (AOCs) were introduced into the PI matrix by using an in situ growth process to inhibit the migration of high-energy electrons. The quantum size effect of the alumina nanoclusters was exploited to synergistically enhance the suppression and scattering of energetic moving electrons by PI-based composite films. The results show that the breakdown field strength of the PI-based composite film (MPI/1.0 vol% AOC) reaches 672.2 kV/mm, and the corona resistance life reaches 7.9 min, which are, respectively, 1.55 and 2.19 times higher than those of the initial PI film. A PI-based composite film with excellent insulating and corona resistance properties was obtained.
研究领域:
材料科学
·
电气工程
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2011
·
IF 2.775
Huihui Ma,Yin Lei,Qiong Jia,Wuping Liao,Li Lin
A synergistic extraction system consisting of sec -octylphenoxy acetic acid (CA12, H 2 A 2 ) and primary amine N1923 (B) for gallium(III), indium(III), and zinc(II) has been developed from chloride medium. Synergistic and antagonistic effects are observed for the title metals at low and high CA12 concentration ratios, respectively. On the basis of the distribution ratios, the values of the separation factors are calculated and used for the discussion of the selectivities between gallium(III)/indium(III) and zinc(II). The synergistic extraction of zinc(II) with the mixtures has been investigated with the methods of slope analysis and constant mole. The synergistic adduct has been determined together with the equilibrium constant and thermodynamic constants.
研究领域:
湿法冶金
·
溶剂萃取
·
无机化学
·
分离科学
·
稀有金属回收
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DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 61
·37014-37022
·
IF 3.119
Shengfu Liao,Jianguo Liu,Long Yan,Qiying Liu,Guanghui Chen,Longlong Ma
Anthraquinones are recognized as high efficiency photocatalysts which can perform various redox reactions in aqueous or organic phases. We have experimentally proven that 2-BrAQ can undergo hydrogen transfer with an alpha-aromatic alcohol under light conditions, thereby efficiently oxidizing the aromatic alcohol to the corresponding product. The yield of 1-phenethanol to acetophenone can reach more than 96%. In subsequent catalyst screening experiments, it was found that the electronegativity of the substituent at the 2 position of the anthraquinone ring and the acidity of the solvent affect the photocatalytic activity of anthraquinones. After using various aromatic alcohol substrates, 2-BrAQ showed good conversion and selectivity for most aromatic alcohols, but showed C–C bond cleavage and low selectivity with non-α-position aromatic alcohols. In order to explore the mechanism of the redox reaction of 2-BrAQ in acetonitrile solution, the corresponding free radical reaction pathway was proposed and verified by density functional theory (DFT). Focusing on calculations for 2-BrAQ during the reaction and the first-step hydrogen transfer reaction between the 2-BrAQ triplet molecule and the 1-phenylethanol molecule, we recognized the changes that occurred during the reaction and thus have a deeper understanding of the redox reaction of anthraquinone compounds in organic systems.
研究领域:
化学
·
催化
·
有机化学
·
理论化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Jie Hao,Fangxia Wu,Rong Tang,Yuanyuan Sun,Dehua Liu,Zhenqing Zhang
Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1 H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides , and in-source fragmented MS for analysis of oxidized polysaccharides . The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0.
研究领域:
化学
·
材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
PLANT DISEASE
·
2025
·
IF 4.4
Tu-Hong Wang,Miss Jingjing Qin,Jinhui Yang,Yu Gao,Miss Wenting Li,Zhiqiang Song,Hua Liu,Jianhong Yan,Wenqiao Deng,Huajiao Qiu,Y. Cheng
Pepper southern blight, caused by Agroathelia rolfsii (Sacc.) Redhead & Mullineux (syn. Sclerotium rolfsii Sacc.), is a serious soil-borne fungal disease. The overuse of chemical pesticides to control this disease has led to pathogen resistance and environmental pollution, making biological control methods a more sustainable alternative. In this study, a strain SEC-482 with significant antagonistic effect against A. rolfsii was isolated from the rhizosphere soil of peppers. It was identified as Bacillus velezensis through morphological, physiological, biochemical and molecular analyses. The strain showed a high inhibition rate of 76.44% ± 0.37% against A. rolfsii in vitro and a control effect of 72.73% on pepper southern blight in pot experiments. Furthermore, it was observed to have a favourable impact on the growth of pepper plants. The genome sequencing and analysis revealed many genes related to antibiosis and growth promotion, as well as 14 secondary metabolite synthesis gene clusters. The strain's volatile organic compounds (VOCs), such as 2,6-diethylpyrazine, isobutyric acid and 3,4-diaminophenol, 3,5-dimethyl-1-prop-2-ynyl-pyrazole, were identified as the main antimicrobial substances. This study demonstrates that B. velezensis SEC-482 has potential for the biological control of pepper southern blight, laying a foundation for subsequent field trials to confirm its practical application value. The identification of VOCs and the exploration of the strain’s fermentation conditions provide valuable insights into its potential applications in sustainable agricultural practices.
研究领域:
植物病理学
·
微生物生物技术
·
生物防治
·
农业微生物学
·
挥发性有机化合物研究
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2026
·
IF 5.1
Peixin Hong,Fengyue Yin,Rongkai Cui,Yongsheng Lin,Xiaoyan Chen,Ting Qiu,Jie Chen
Sec -butyl alcohol (SBA) is a crucial chemical intermediate and solvent in organic synthesis. The transesterification of sec -butyl acetate (SBAC) with methanol (MeOH) is a key SBA production process due to straightforward reaction conditions and raw materials easily available, but conventional catalysts suffer from high corrosivity and poor recyclability, increasing costs. Herein, we report a series of novel heterogeneous catalysts of TEOS-[Ch][Im]- x with differential loading amount of choline imidazolate ([Ch][Im]) supported on SiO 2 . [Ch][Im], for the first time, is employed not only as a basic catalyst to facilitate the formation of SiO 2 , but also as a catalytic moiety immobilized on the SiO 2 matrix via H-O hydrogen bonds, thus enabling the fabrication of efficient SiO 2 -based catalysts through a one-pot reaction. By optimization of catalytic conditions for optimal catalyst TEOS-[Ch][[Im]-12, over 50% SBAC conversion is achieved in 60 min, and the conversion rate reaches 61.58% under the reaction temperature of 67 ℃ , nMeOH: nSBAC = 8.8:1, and catalyst dosage 9 wt% conditions after response surface methodology (RSM) optimization. More importantly, the catalyst exhibits excellent reusability and cycling stability without any noticeable deactivation over five consecutive reaction cycles. Density functional theory (DFT) calculations and in situ diffuse reflectance infrared Fourier transform spectroscopy ( in situ DRIFTs) results further confirm that the functionalized [Im] − anions could activate methanol to form the key adsorbed CH 3 O* intermediate, which then undergoes a nucleophilic reaction with SBAC to yield SBA. This facile synthetic strategy thus endows the catalyst with considerable application potential for green catalytic transesterification processes.
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DOI
高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Shiqi Li,Fan Zhang,Qinjun Sun,Zhanfeng Li,Yanxia Cui,Ting Ji,Wei Qin,Furong Zhu,Yuying Hao
High-quality perovskite films are essential for high-performance perovskite solar cells (PSCs). Here we first proposed a polar anti-solvent technology of sec-pentyl alcohol (2-PA) for the fabrication of perovskite films. Our investigations have proven that 2-PA, as a better anti-solvent than conventional those with non- and high-polarity, enables the fabrication of uniform and dense perovskite films with mirror-like surface and film-through large grains. We found that moderate polar solvent more advantageously influences the crystallinity and morphology of perovskite films by extracting thoroughly the residual solvent and promoting a more complete and fast transformation from the lead polyhalide framework to the targeted perovskite film. By our proposed way, the best performing PSCs based on methylammonium lead iodide showed a power conversion efficiency (PCE) of over 17% under AM 1.5G illumination with high reproducibility and no photocurrent hysteresis. Our investigation indicates that sec-pentyl alcohol as anti-solvent could be an universal method for the preparation of hybrid organic-inorganic perovskite film.
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Tiange Ma,Xingjiang Li,Manuel Montalbán-López,Xuefeng Wu,Zhi Zheng,Dongdong Mu
Lactococcus lactis is a crucial food-grade cell factory for secreting valuable peptides and proteins primarily via the Sec-dependent pathway. YidC, a membrane insertase, facilitates protein insertion into the lipid membrane for the translocation. However, the mechanistic details of how YidC affects protein secretion in L. lactis remain elusive. This study investigates the effects of deleting yidC1/yidC2 on L. lactis phenotypes and protein secretion. Compared to the original strain, deleting yidC2 significantly decreased the relative biomass, electroporation efficiency, and F-ATP activity by 25%, 47%, and 33%, respectively, and weakened growth and stress resistance, whereas deleting yidC1 had a minimal impact. The absence of either yidC1 or yidC2 reduced target proteins secretion. Meanwhile, there is a considerable alteration in the transcription levels of genes involved in the secretion pathway, with secY transcription increasing over 135-fold. Our results provide a theoretical foundation for further improving target protein secretion and investigating the YidC function.
研究领域:
微生物学
·
生物技术
·
蛋白质工程
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 36
·12560-12567
·
IF 7.059
Linlin Qiu,Lika Dong,Deqiang Mei,Wei-Hsiang Chen,Lixin Song,Jieqiong Wang,Jiacheng Zou,Pei-Cheng Jiang,Pingfan Du,Jie Xiong
Perovskite films can be prepared using sec-butyl alcohol (2-BA) by a one-step antisolvent assisted method. However, 2-BA dissolves a necessary perovskite precursor, methylammonium iodide, CH3NH3I, (MAI), which is lost during the fabrication, leaving behind residues of another perovskite precursor, PbI2. The resulting perovskite films show reduced power conversion efficiency (PCE) and poor stability to ambient conditions. In this work, we propose an elegant strategy, i.e., the introduction of a small amount of MAI dissolved in the antisolvent 2-BA (1 mg mL−1). The additional MAI can react with the residual PbI2 during the fabrication to form the desired organic–inorganic hybrid perovskite material, CH3NH3PbI3. The high-quality of the perovskite films obtained can provide larger grain sizes and smoother surfaces, with an ideal PCE of 19.29% and superior moisture stabilities.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2026
·
IF 9.8
Jinqi Shen,Lei Liu,Wenwen Yu
In this study, 28 rice starches with varying amylose contents ranging between 0.64 % ~ 41.19 % were analyzed using size-exclusion chromatography (SEC), fluorophore-assisted carbohydrate electrophoresis (FACE), and high-performance anion-exchange chromatography (HPAEC). All methods reproduced canonical multi-modal chain length distribution (CLD) but differed in reliability: SEC was limited by band broadening, HPAEC resolved medium chains but became noisy at very high degree of polymerization above ~68. In contrast, FACE combined high resolution of short and long chains with mild processing, providing the most robust and reproducible profiles, which is further confirmed by the analysis of compact, short-chain-rich topologies in low-amylose starches. Importantly, no statistically significant correlations were detected between FACE-derived CLD parameters and the in vitro digestion parameters of freshly cooked rice under the present sample size, highlighting the need for integrated approaches to link starch molecular structure with functional properties.
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Xia Yin,Chaochen Du,Jingjing Li,Wenbo Jiang,Yigang Ding,Hongmei Du,Zhiping Du,Zhiguo Yan
Carbonate esters and esters were commonly used as solvents, reaction carrier, and additives in organic synthesis, the pharmaceutical industry, and processing industries. Vapor–liquid equilibrium (VLE) data are vital to the separation process or process simulation for separating solvents. Therefore, it is necessary to enrich a VLE database for carbonate esters and esters. In this study, isobaric VLE data for three systems of isopropyl acetate + diethyl carbonate (DEC), sec-butyl acetate + DEC, and DEC + isoamyl acetate at 101.3 kPa were determined for enriching the group interaction parameters for carbonate esters. Meanwhile, the thermodynamic consistencies of the VLE data were tested using the Van Ness method modified by Fredenslund et al. The Wilson, NRTL, and UNIQUAC models were used and found to have good consistency for all binary systems between the experimental and simulated data. At the same time, the VLE data were correlated by the UNIFAC-DMD model to supplement the group parameters for carbonate esters. The average absolute deviation (AAD) of the temperature of the activity coefficient model and the UNIFAC-DMD model is not less than 0.16 K, and the AAD of the vapor phase mole fraction is not less than 0.0016. In addition, azeotropy did not occur in all binary systems.
研究领域:
化学工程
·
热力学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）