FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Zexiang Lyu,Fen Yue,Xiuyin Yan,Jianfeng Shan,Danlei Xiang,Christian Marcus Pedersen,Chunju Li,Yingxiong Wang,Yan Qiao
Hydrogenolysis is necessary for preparing various value-added chemicals from glycerol. Routine methods like GC and HPLC are not sufficient for analysis the reaction mixtures because the products usually have high boiling or similar polarity, especially when new chromatographic peaks are found which requires other technologies such as NMR . Although they were developed for years, but either DOSY or 1D selective TOCSY NMR has nature limitations. Herein we took their advantages and combined them to analyse glycerol hydrogenolysis mixtures for the first time. A model reaction mixture was first pseudo separated in DOSY spectrum, and 1D selective gradient TOCSY was further applied to assign the overlapped signal which could not be confirmed just by DOSY. A genuine reaction mixture was tried afterwards, and main signals could be assigned well in DOSY diffusion dimension. Notably, n-propanol was found as by-product by 1D selective gradient TOCSY, which is not visible in DOSY spectrum. The experimental results demonstrate that the combination of these two NMR methods could provide a fast, effective, feasible and reliable way for the identification of glycerol hydrogenolysis mixtures and is expected to apply in other research areas.
研究领域:
化学
·
生物化学
·
分析化学
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TALANTA
·
2026
·
IF 6.7
Lei Ding,Ruochen Zhang,Wenchan Deng,Feifei Chen,Shuangshuang Liu,Jinsheng Lin,Cuirong Sun
Vericiguat (VER), a novel soluble guanylate cyclase agonist for heart failure, was subjected to comprehensive forced degradation studies to assess its stability and elucidate degradation pathways. The study was conducted in accordance with ICH guidelines, including alkaline, acidic, oxidative, photolytic, and thermal stress conditions. And tentatively structural identification of degradation impurities was carried out using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). The results indicated that VER was susceptible to degradation under alkaline (NaOH) and hydrogen peroxide (H 2 O 2 ) oxidative conditions, yielding nine degradation impurities (DIs 1-7, 9, 10). Among these, eight have not been previously reported, with the exception of DI-7. Moreover, under a newly introduced free-radical oxidation condition using benzoyl peroxide (BPO), two additional novel impurities (DI-8 and DI-11) were generated. And two major degradants (DI-3-2 and DI-5) were isolated and their structures were confirmed by 1Dimension/2Dimension-Nuclear Magnetic Resonance (1D/2D-NMR) analysis. Based on the structures of the degradation impurities, the degradation pathways were elucidated and the molecular stability was investigated. The results demonstrate that the primary degradation mechanisms involved pyrimidine ring cleavage, oxidation of the amino group, hydrolysis of ester and amide bonds, as well as intramolecular cyclization and rearrangement. This study successfully established a comprehensive impurity profile for VER and provided robust scientific data for formulating its quality standards, thereby supporting stability assessment and quality control during pharmaceutical development.
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JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2024
·
IF 4
Ting Shi,Gangcheng Wu,Qingzhe Jin,Xingguo Wang
Camellia oil has become one of the most popular edible vegetable oils especially in China. It can be obtained by cold-pressing (CPE), soxhlet extraction (SE), aqueous enzymatic extraction (AEE), and supercritical carbon dioxide extraction (SC-CO 2 ), while research on their efficient identification is limited. Thus, in this study, proton nuclear magnetic resonance ( 1 H NMR) and conventional chemical analysis, respectively coupled to chemometrics, were employed to compare the camellia oils, produced by CPE, SE, AEE, and SC-CO 2 . The results showed an obviously overlapping among those four different extracted camellia oils, in both principal component analysis (PCA) and hierarchical clustering analysis (HCA), when using fatty acids as input variables. While two obtained PCA models showed good discrimination, according to the minor component compositions (α-tocopherol, squalene, stigmasterol, β-sitosterol, β-amyrin and lanosterol) and 1 H NMR spectra, respectively. Additionally, by means of variable importance for the projection (VIP) scores, less 10 dominant 1 H NMR spectra signals were screened out as detailed markers for different camellia oils classification. Therefore, 1 H NMR combined with chemometrics may be applied as an efficient technique to classify different extracted camellia oils and potentially other vegetable oils.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
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Journal of Physical Chemistry C
·
2023
·
IF 3.7
Huiyan Wu,Hailong Huang,Lingzhi Cao,Yiyang Liu,Jianxing Dai,Cuilan Ren,Min Ge,Yuan Qian,Shuxian Hu,Xiaobin Fu,Hongtao Liu
In this study, it was demonstrated that Na+ ionic doped crystals could be formed during the solidification of FLiNaK melts. The ionic adulterating behavior between Li+, Na+, and K+ ions was investigated in detail by using various 1D/2D solid-state NMR methods and theoretical calculations. 2D 19F–23Na and 19F–7Li HETCOR NMR showed that the Na+ ions could be doped into LiF and KF crystals to generate new adulterating phases. Furthermore, the doped ionic Na+ ions exhibited different dynamics in LiF and KF crystals, which is correlated to the bonding length of the lattice and the Na–F coordinated interactions. This study provides more insights into the ionic doped crystal phase formation in such simple alkali metal fluorides, which may be of greater significance in the application as optical devices.
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DOI
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INTERNATIONAL DAIRY JOURNAL
·
2022
·
IF 3.572
Xianglin Yue,Junru Sun,Ru Zhao,Jinsheng Zhang
Rapid screening and early warning of pathogenic bacteria in food is the key to prevent and control the spread of foodborne diseases . Biotin–streptavidin system and membrane filtration technology were combined to develop a novel nuclear magnetic resonance (NMR) immunosensor based on biomacromolecule O-carboxymethyl chitosan (O-CMCS) target gadolinium (Gd) probe for rapid detection of Salmonella anatum in milk. Under optimal experimental parameters, the proposed NMR immunosensor could detect Salmonella in milk with a limit of detection of 1.8 × 10 4 cfu mL −1 within 2 h. Furthermore, the immunosensor exhibited good specificity, sensitivity and reproducibility, which could achieve the direct determination of biological samples with complex composition. Hence, the developed assay might have great application potential for the rapid detection of Salmonella in food.
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DOI
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Food Bioscience
·
2023
·
IF 5.2
Fengli Lian,Jun-Hu Cheng,Ji Ma,Da-Wen Sun
The effects of combining roasting and steam cooking at 200 °C for various cooking times (10, 15, 20, 25 and 30 min) on water status and distribution and the microstructure and physicochemical properties of pork patties were analyzed with low-field nuclear magnetic resonance and magnetic resonance imaging analyses, as compared with roasting alone. The findings demonstrated that the addition of steam can alleviate the denaturation of protein and reduce the mobility of water molecules. Roasting-steam cooking (RS) had no negative effect on the TBARS value and surface hydrophobicity. Furthermore, the RS treatment has a higher moisture content, WHC and texture than roasting cooking. Proton density maps displayed a gradual decrease in water intensity, suggesting the gradual expelling of inside water to the surface as drip loss. Therefore, the findings revealed that water status evolution during RS significantly changed the microstructure and protein structure of the meat.
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INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Jingbo Yu,Lili Hu,Yujing Shen,Jinjun Ren
A series of glasses with composition 60NaPO3–(40-x)CdF2–xYF3–yEr2O3 were synthesized via melt-quenching methods and subsequently heat-treated to obtain upconversion luminescent glass ceramics containing NaYF4:Er crystals. Hexagonal and/or cubic NaYF4 crystals were controlled to be bred in the glasses by changing the glass composition. The structure evolution driven by crystallization was characterized using advanced solid-state nuclear magnetic resonance (SSNMR) techniques. The SSNMR results reveal that the Y/Na ratio determines the crystalline phases of NaYF4 precipitated in this glass system. Y3+ attracts extra F– ions from P5+ and Cd2+ during crystallization because of its stronger ability to attract F– ions, leading to most Y3+ ions being crystallized into the NaYF4 crystals. The paramagnetic broadening effect of the Er3+ ions on NMR signals as well as the upconversion luminescence results indicate that, before crystallization, most Er3+ ions are surrounded by oxygen within the glasses; however, after crystallization, almost all of them enter the NaYF4 crystals. On the basis of this local structure investigation, a composition design strategy is developed to obtain highly efficient upconversion luminescent glass ceramics.
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PubMed
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JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2021
·
IF 4.556
Xiuming Jiang,Denghui Yang,Guoqiang Xiang,Leqian Hu
In this work, cis and trans fatty acid (FA) contents in edible oils was determined using 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy. The comparison of 1 H NMR spectra of edible oil and cis-trans isomerized oil showed that they were different in three regions: (1) 2.880 - 2.650 ppm caused by bis-allylic protons; (2) 2.140 - 1.900 ppm due to allylic protons; and (3) 1.030 - 0.930 ppm due to methyl protons of linolenic acyl groups. The 1 H NMR signals in these regions were combined with partial least squares method to predict contents of cis/trans fatty acids in edible oils. The results showed that the predicted values were consistent with the gas chromatography-measured values and had a good linear relationship with a correlation coefficient (R 2 ) of above 0.98. This work demonstrates that 1 H NMR spectroscopy was successfully used to determine the composition of both cis and trans fatty acids in edible oils.
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JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2019
·Vol. 56
·期 2
·1027-1036
·
IF 1.85
Yang Shuang,Liu Jingsheng,Zheng Mingzhu,Zhao Chengbin,Cao Yong,Dong Yanjiao,Yaqoob Sanabil,Xiao Yu,Xu Xiuying
Cordyceps militaris ( C. militaris ) was utilized to ferment cornmeal by solid state fermentation. The main objective of this study was to investigate effect of fermentation on the dynamic state of water and microstructure distribution of water within cornmeal with Low-field nuclear magnetic resonance, as well as the effect on composition and microstructure properties. The spin–spin relaxation time (T 2 ) showed significant changes in solid-state fermented cornmeal. Principal component analysis further revealed that the variations within different fermentation stage could be discriminated by the T 2 parameters. Bulk water (T 22 ) was the main form of water present and lost in substrates. The weights of different indicators, as assessed by multiple regression analysis, demonstrated that there was a strong correlation between starch and T 2 relaxation. Scanning electron microscopy demonstrated that fermentation can cause the appearance of micropores. The longer relaxation time of T 22 during logarithmic period can be interpreted as a loosening of the structure at the starch hydrolysis, introducing more water into the structure. Thus, the differences in composition and structure of the substrate at different fermentation time produce different T 2 values.
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JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2016
·Vol. 27
·期 11
·2120-2126
·
IF 1.096
Dong Jian-Wei,Cai Le,Fang Yun-Shan,Duan Wei-He,Li Zhen-Jie,Ding Zhong-Tao
Radix et Rhizoma Rhei has been recognized for centuries in traditional medicine for its multiple pharmacological actions. The free anthraquinones including physcion, chrysophanol, emodin, rhein, and aloe-emodin are the main bioactive components in Radix et Rhizoma Rhei. In the present study, a fast quantitative 1H nuclear magnetic resonance (q-HNMR) method for the determination and quantitation of five free anthraquinones in Radix et Rhizoma Rhei was developed. Validation of the quantitative method was performed in terms of specificity, accuracy, precision, and stability. The results showed that the solvent acetone-d6 enabled satisfactory separation of the signals to be integrated. Five anthraquinones in Radix et Rhizoma Rhei could be quantified accurately using featured signals from 1H NMR. This work implied that q-HNMR represents a feasible alternative to high-performance liquid chromatography (HPLC)-based methods for quantitation of anthraquinones in Radix et Rhizoma Rhei and is suitable for the quality control of Radix et Rhizoma Rhei.
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Polymers
·
2024
·Vol. 16
·期 23
·3254
·
IF 4.7
Jiaqi Wang,Zhaoyutian Chu,Sijia Zheng
Considering the demand for the construction of a sustainable future, it is essential to endow the conventional thermoset silicone adhesive with reuse capability and recyclability. Although various research attempts have been made by incorporating reversible linkages, developing sustainable silicone adhesives by natural linkers is still challenging, as the interface between the natural linker and the silicone is historically difficult. We exploited the possibility of utilizingα-lipoic acid, a natural linker, to construct a sustainable silicone adhesive. Via the simultaneous ring-opening reaction between the COOH and epoxide-functionalized silicone and the polymerization of theα-lipoic acid, the resulting network exhibited dynamic properties. The shear strength of the LASA90 presented strong adhesion (up to 88 kPa) on various substrates including steel, aluminum, PET, and PTFE. Meanwhile, reversible adhesion was shown multiple times under mild heating conditions (80 °C). The rheology, TG-DTA, DSC, and1H NMR showed that the degradation of the LASA occurred at 150 °C via the retro-ROP of the five-membered disulfide ring, indicating their recyclability after usage. Conclusively, we envision that a silicone adhesive based onα-lipoic acid as a natural linker is more sustainable than conventional silicone thermosets because of its desired properties, strong adhesion, reversibility, and on-demand heat degradation.
研究领域:
材料科学
·
化学工程
·
可持续发展
·
粘合技术
·
聚合物化学
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Qing Zhang,Jiaping Ke,Piaopiao Long,Mingchun Wen,Zisheng Han,Liang Zhang,Mengting Zhu
The linoleic acid reaction models were set at 150 °C for 120 min, and its oxidation process was monitored by nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry (GC-MS). Results showed that no furan was formed from linoleic acid without heating, while furan accumulated throughout the heating process. Linoleic acid ran out within 30 min, which indicated that furan was formed mainly from the intermediate oxidation products of linoleic acid after 30 min. It should be noticed that the content of (E,E)-2,4-decadienal reached maximum once the linoleic acid ran out and then decreased with the formation of furan. Multivariate statistical analysis suggested that (E,E)-2,4-decadienal was the most important aldehyde related to furan formation during linoleic acid oxidation. To prove this assumption, the variation of furan from (E,E)-2,4-decadienal reaction models heating at 150 °C for 60 min was also studied. Results showed that the content of furan increased with the oxidation of (E,E)-2,4-decadienal. Furthermore, NMR and GC-MS data proved that (E,E)-2,4-decadienal could be oxidized to 4,5-epoxy-(E)-2-decenal. In conclusion, our results supported (E,E)-2,4-decadienal and trans-4,5-epoxy-(E)-2-decenal as critical intermediate products of furan formation from linoleic acid oxidation.
研究领域:
化学
·
食品科学
·
分析化学
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PubMed
高影响因子
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