FOOD CHEMISTRY
·
2015
·
IF 3.391
Zhengzong Wu,Enbo Xu,Jie Long,Xiaowei Pan,Xueming Xu,Zhengyu Jin,Aiquan Jiao
The application of attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy (RS) and combination of ATR-IR and RS for measurements of total antioxidant capacity (TAC) and total phenolic content (TPC) of Chinese rice wine (CRW) were investigated in this study. Synergy interval partial least-squares (SiPLS), support vector machine (SVM) and principal component analysis (PCA) were applied to process the merged data from two individual instruments. It was observed that the performances of models based on the RS spectra were better than those based on the ATR-IR spectra. In addition, SVM models based on the efficient information extracted from ATR-IR and RS spectra were superior to PLS models based on the same information and PLS models based on ATR-IR or RS spectra. The overall results demonstrated that integrating ATR-IR and RS was possible and could improve the prediction accuracy of TAC and TPC in CRWs.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2026
·
IF 4.4
Shenhui Yu,Xingfen Huang,Xingyue Shi,Nemin Yang,Bangban Zhu,Haitao Wang,Jieyuan Zheng,Shengbin Shi,Deliang Wang,Qingyue Wang,Khak Ho Lim,Xuan Yang,Pingwei Liu,Wen-Jun Wang
Mechanistic understanding of polymerization kinetics at elevated pressure requires quantitative, time-resolved access to reaction dynamics. Herein, we developed an integrated framework coupling in situ high-pressure ATR-IR spectroscopy with a kinetic model based on the method of moments. Using ethylene/maleic anhydride (E (1)/MAH (2)) copolymerization as a benchmark, this platform enabled real-time quantification of monomer consumption and in situ determination of copolymer composition, directly confirming strict alternating incorporation. The kinetic model showed excellent agreement with experiments, with deviations below 10%. Analysis revealed the cross-propagation of MAH to ethylene-terminated radicals ( k 12 ≈ 5.62 × 10 3 L mol −1 s −1 ) is over an order of magnitude faster than the reciprocal step ( k 21 ≈ 3.92 × 10 2 L mol −1 s −1 ), identifying the latter as rate-determining. Extrapolation of the model guided the precise synthesis of a high-molecular-weight copolymer ( M w = 107 kDa). This work establishes a generalizable in situ platform for elucidating kinetics in complex polymerization systems at elevated pressure.
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Hai-Fang Mao,Hong-Qing Fu,Ji-Bo Liu,Yun Zhao
A novel iron-pyridine-based chelate Fe-PYPA was synthesized via a facile and green strategy. The chelate served as a highly efficient catalyst toward CO 2 cycloaddition . A 95.7% PO conversion and a 98.4% PC selectivity were achieved under moderate conditions. Even under solvent-free conditions, Fe-PYPA could achieve a 93.6% conversion and 98.2% selectivity, acting as a robust and efficient catalyst toward CO 2 cycloaddition. Moreover, the as-prepared catalyst showed desirable catalytic activity , good recyclability , remarkable thermo-stability and ideal compatibility to a variety of epoxy substrates. In-situ ATR-IR spectroscopy was used as a powerful tool to gain process understanding for the whole conversion from CO 2 to cyclic carbonate under atmospheric pressure in the presence of TBAI. The process of PO’s ring opening, activation and insertion of CO 2 and the formation of cyclic carbonate were illuminated explicitly through the change of characteristic absorption peaks, providing direct and visual evidence for the mechanism proposed. The present work paves a new way for theoretical and experimental explorations on novel catalyst design and process understanding for highly-efficient greenhouse gas re-utilization.
研究领域:
化学工程
·
催化化学
·
环境科学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2022
·
IF 4.831
Ying Ju,Chunling Yin,Yan Zhang,Xiangru Meng,Liuchuang Zhao,Leqian Hu
Quality evaluation and consistency evaluation of drugs are the keys to ensure the therapeutic effect and safety of drugs. In this study, attenuated total refraction infrared (ATR-IR) spectroscopy and near-infrared (NIR) spectroscopy combined with chemometrics were used for rapid detection and quality evaluation of active components of Shuang-Huang-Lian injection (SHLI), a traditional Chinese medicine preparation commonly used in China. Taking the chromatographic detection results as a reference, the partial least squares (PLS) model based on ATR-IR and NIR data was constructed by removing the bands with serious noise interference and low signal frequency band. The results showed that the PLS model achieved satisfactory results for the prediction of the three active components (chlorogenic acid, baicalin and phillyrin) in SHLI, indicating that the two spectral techniques combined with the PLS regression method could be successfully used for rapid quantitative analysis of the three active ingredients in SHLI. Relatively, the PLS model based on the ATR-IR spectrum has higher R 2 and smaller RMSE than it based on the NIR spectrum. Furthermore, based on the rapid quantitative analysis of the three active ingredients in SHLI, the quality of 140 SHLI samples from seven manufacturers was evaluated by TOPSIS (technique for order preference by similarity to the ideal solution) analysis, and the consistency of different batches of SHLI products from the same manufacturer was evaluated. The results showed that there were differences in the quality of SHLI produced by different manufacturers, and the quality of different batches of SHLI produced by the same manufacturer was not completely consistent. In conclusion, ATR-IR and NIR spectroscopy combined with chemometrics can be used for accurate and rapid quantitative analysis and quality evaluation of SHLI. This study provides a good idea for the rapid quantitative analysis and quality evaluation of drugs or food based on spectroscopic technology and chemometrics.
研究领域:
中药分析
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药物质量控制
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光谱学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2026
·
IF 7.3
Wei-Yi Zhang,Xindi Xu,Yunfang Yan,Yaning Guan,Xian-Yin Ma,Tian-Wen Jiang,Kun Jiang,Wen-Bin Cai
Facile fabrication of thin metal films on protected silicon internal reflection elements (IREs) is essential for electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) in various pH electrolytes to cater for broad application scenarios. In this technical note, we report a facile and low-cost chemical deposition tactic to fabricate robust Au, Pt, and Pd films on resistive boron-doped diamond-coated silicon wafer (BDD/Si) IREs, enabling electrochemical ATR-SEIRAS measurements with extended low-frequency detection in harsh acidic and alkaline solutions. This is achieved by initial seeding of metallic nuclei through the ultrafine nanochannels of the BDD protective layer, followed by further growth into a conductive metal film. Compared to those prepared by physical deposition, the as-deposited metal films on BDD/Si IRE exhibit excellent stability against multiple potential cycling and hydroxide attack as well as a higher IR absorption for surface CO species. Based on this tactic, in situ ATR-SEIRAS study of CO adsorption on Au, Pt, and Pd electrodes in solutions of pH1 and pH14 is comparatively probed, together with that of the interfacial hydrogen-bond broken H2O.
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Ling Liu,Yanbo Li,Man Xu,Cunwen Wang
Two-dimensional Co ultrathin metal–organic framework nanosheets (Co-UMOFNs) were synthesized and blended into poly (ether block amide) (PEBA) to prepare composite mixed matrix membranes on PVDF supports for the pervaporation of phenol aqueous solution. The membranes were characterized by XRD, ATR-IR, TGA, CA and SEM measurements. Effects of the Co-UMOFNs loading, feed temperature and feed concentration on phenol separation performance were investigated. The results showed that Co-UMOFNs have a two-dimensional layered morphology and have good compatibility with the PEBA. A “brick and mortar” architecture morphology was achieved after incorporating Co-UMOFNs into the PEBA membrane. The amorphous PE segments in the PEBA were turned into a crystalline structure, restricting the motion of PE segments. The filling of Co-UMOFNs slightly improved the thermal stability and hydrophobicity as well. With the increase of the Co-UMOFNs loading from 0% to 40%, the phenol separation factor increased from 27 to 45, and the total flux decreased from 1.2 kg m -2 h - 1 to 0.42 kg m -2 h - 1 , when separation of 1000 ppm phenol solution at 70 °C. The interlayer galleries induced by the Co-UMOFNs stacking increased the tortuosity, and the crystalline structure of the Co-UMOFNs-PEBA improved the energy barriers of water penetration. Therefore the water flux was inhibited and the phenol separation factor increased. Depression of water permeation can be another protocol to prepare high-performance organophilic pervaporation membranes.
研究领域:
材料科学
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化学工程
·
膜技术
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DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 8
·925
·
IF 4.146
Qijun Wang,Ya-Wei Zhou,Zhao Jin,Chunguang Chen,Hong Li,Wen-Bin Cai
Carbon-supported PtRu nanoalloy (PtRu/C) is widely used as the anode catalyst for direct methanol fuel cells (DMFC), and an aqueous phase synthesis of PtRu/C is in high demand due to for energy-saving and environmentally-benign considerations, however, it is very challenging to attain stoichiometric reduction, good dispersion and a high alloying degree. Herein, we report a facile aqueous phase approach with dimethylamine borane (DMAB) as the reducing agent to synthesize a PtRu/C(DMAB). TEM, XRD, XPS and ICP-AES characterizations indicate that the structural parameters in the PtRu/C(DMAB) are improved significantly as compared to those obtained in a PtRu/C(NaBH4) and a commercial PtRu/C, contributing to an enhanced electrocatalytic performance. It turns out that the PtRu/C(DMAB) exhibits the highest methanol electro-oxidation (MOR) performance among all of the tested samples, with the peak current up to 1.8 times as much as that of the state-of-the-art commercial PtRu/C, corroborating the highest output power density in comparative DMFC tests. In-situ attenuated total reflection infrared (ATR-IR) spectroscopy correlates the higher methanol electro-oxidation performance of the PtRu/C(DMAB) with its enhanced CO resistance and CO2generation. This simple aqueous synthetic approach may provide an alternative route for developing efficient anode electrocatalysts of DMFCs.Keywords:PtRu/C catalyst;methanol electro-oxidation reaction;aqueous phase synthesis;dimethylamine borane;direct methanol fuel cell;in-situ ATR-IR
研究领域:
化学
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材料科学
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能源科学
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产品关联
DOI
高影响因子
NORDIC PULP & PAPER RESEARCH JOURNAL
·
2021
·Vol. 36
·期 1
·21-32
·
IF 1.04
Guozheng Chen,Jinquan Wan,Yongwen Ma,Yan Wang
The macroscopic and microscopic properties of old newsprint pulp with xylanase, MLac/Glu (modified laccase-glutamate system), and X-MLac/Glu (xylanase synergistic modified laccase-glutamate system) pretreatment was investigated by means of fiber quality measurements (FQA), attenuated total reflectance-infrared spectroscopy (ATR-IR), headspace gas chromatography (HSGC), X-ray diffract ion method (XRD), Low-temperature nitrogen absorption and scanning electron microscopy (SEM). Results showed that, compare with the control pulp, the brightness and lightness (
L
∗
) of hydrogen peroxide bleached pulp after X-MLac/Glu pretreatment increased by 5.86 % ISO and 3.58 %, respectively. FQA analysis revealed that coarseness and fine fiber content increased slightly. The content of carboxyl groups and water retention value increased remarkably by 31.11 % and 39.22 %, respectively. The paper physical analysis showed that the paper strength properties have improved significantly. The crystallinity of cellulose decreased by 3.82 % due to X-MLac/Glu pretreatment. ATR-IR analysis indicated some non-cellulose components are removed. The BJH average pore size and BET specific surface area increased after enzyme pretreatment. The SEM analysis showed that through X-MLac/Glu treatment the fiber surface becomes rough and the connections between the fibers become tighter, more fibrils appeared.
研究领域:
制浆造纸科学
·
生物技术
·
材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）