Environmental Science-Nano
·
2017
·Vol. 4
·期 3
·577-584
·
IF 6.047
L. W. Zhang,H. Li,F. Y. Chen,D. Zhang,M. Wu,B. Pan,B. S. Xing
Although the Brunauer–Emmett–Teller (BET) measurement based on gas adsorption is the widely recognized method of characterizing the specific surface area (SSA) and pore structures, this method is limited to the analysis of dried particles, and thus has little relevance to the determination of the behavior and performance of those particles in liquids (e.g., wetted surface). In this study, the BET-N2 surface area of dehydroxylated silica NPs was correlated with phenol and β-naphthol sorption in hexane, but not in water. Clearly, the BET-N2 surface area could not explain the sorption data. We measured the surface –OH density (nm−2) of silica NPs after hydroxylation and observed more –OH groups on surfaces of less curvature (bigger particle sizes), which may explain the higher sorption of phenolic chemicals on larger particles (but smaller surface area) through hydrogen bonding. The silica NPs were less aggregated after hydroxylation, which also contributed partly to the increased sorption after hydroxylation. Thus, the silica NP surface area measured in the dry state will not provide useful information to understand the actual sorption of phenolic chemicals. We applied a method based on solvent relaxation NMR to measure the silica NP (before and after hydroxylation) surface properties in different solvents to correlate with the sorption data. The sorption data in different solvents were more easily correlated with the relaxation data in the corresponding solvents. We thus call the readers' attention that the surface area measured only in the circumstances relevant to the sorption system can be applied to understand the interfacial properties.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Haonan Liu,Ruixi Liu,Ali Hassan Bhatti,Mamoona Waris,Qingzhi Zhang,Yingjie Niu,Francesco Barzagli,Ruqi Xiao,Chao’en Li,Rui Zhang
Accurately predicting CO 2 equilibrium solubility is essential for optimizing amine-based sorbents in carbon capture processes. However, traditional experimental approaches require extensive testing, making data collection time-consuming and often incomplete. In this study, we address this challenge by developing six machine learning models to predict CO 2 solubility in three dual-amine blends (MEA + MDEA, MEA + DEEA, and MEA + DMEA), significantly reducing the reliance on labor-intensive experiments. The PSO-BPNN model achieved the highest accuracy, with errors below 2.2 %, demonstrating the potential of machine learning to provide reliable solubility data without exhaustive experimental measurements. Additionally, we experimentally evaluated the CO 2 absorption and desorption performance of MEA-based blends, complemented by 13 C NMR spectroscopy to elucidate reaction mechanisms. Among the tested systems, the 2 M MEA + 3 M DEEA blend exhibited the highest CO 2 loading, fastest desorption rate, and lowest heat duty compared to 5 M MEA, underscoring its potential as a superior sorbent for energy-efficient CO 2 capture.
研究领域:
化学工程
·
环境科学
·
人工智能
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DOI
高影响因子
Journal of Magnetic Resonance Open
·
2025
·
IF 2
Bowen Han,Jing He,Shaohua Huang
Chiral amino acids play an indispensable role in living organisms. Diffusion-ordered NMR spectroscopy is an effective NMR tool and a noninvasive analytical method for the analyses of mixture without the need for physical separation of the analytes. However, conventional diffusion-ordered NMR spectroscopy method usually fails to resolve the mixtures of chiral amino acids because of their same molecular masses, sizes, and shapes. Microcrystalline cellulose has been gradually gained more and more interest owing to its wide compatibility, surface area, excellent separation efficiency, non-toxicity, cost-effective, and mechanical stability in many fields. Herein we provide a fast, simple, specific and sensitive method to resolve some D and L-amino acids mixtures by using microcrystalline cellulose as a matrix. This work recognized some D and L- proteinogenic amino acid enantiomers with diffusion-ordered NMR for the first time.
研究领域:
分析化学
·
生物化学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2011
·Vol. 13
·期 32
·14542-14549
·
IF 3.454
Kelei Zhuo,Yujuan Chen,Jing Chen,Guangyue Bai,Jianji Wang
Extensive applications of ionic liquids (ILs) may result in their accumulation in the ecological environment and organisms. Although ILs are popularly called “green solvents”, their toxicity, in fact, has been exhibited. Therefore the interaction of ILs with biomolecules is a cutting-edge research subject. Herein, the interactions of 1-butyl-3-methylimidazolium carboxylate ionic liquids ([C4mim][HCOO], [C4mim][CH3COO] and [C4mim][CH3CH2COO]) with glucose in water were studied for their volumetric properties, viscosity, conductivity and NMR spectra. Limiting apparent molar volumes (V0Φ,IL), viscosity B-coefficients, limiting molar conductivities (Λ0) and Walden products (Λ0η0) were evaluated for the ILs in glucose + water solutions. Volumetric interaction parameters were also obtained from the transfer volumes of the ionic liquids. The contributions of the solvent properties (B1) and the ionic liquid–solvent interactions (B2) to the B-coefficient were extracted, together with molar activation energies (Δμ0≠IL) of the ionic liquids for viscous flow of the aqueous glucose + IL solution. In addition, the 13C and 1H NMR spectra of methyl β-D-glucopyranoside and ILs in β-D-glucopyranoside + IL + D2O were studied. The NMR results show that no special and strong interactions were observed between glucopyranoside and the ILs. However, it was confirmed that the H2 on the imidazolium ring has more activity (acidity) than atoms H4 and H5. The macro-properties and their changes were also discussed in terms of the size, structure and solvation of the ILs and glucose.
研究领域:
生物化学
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环境科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 28
·期 7
·1-11
·
IF 3.097
Yu Xueyi,Fang Zeming,Qin Yijing,Lu Dong,Liu Qianfa,Luo Li,Lin Zhiyong,Wang Ke
Thermosetting Polyphenylene oxide (PPO)/Triallyl isocyanurate (TAIC) based composite systems have attracted considerable attentions in recent years due to their excellent performance as the substrate for printed circuit boards (PCBs) used for 5G networks. Since the residuals of -OH and -C = C- groups have significant effects on the properties of the substrate, especially the dielectric properties and thermal stability, it is critical to establish valid methods for characterizing these systems. In this work, FTIR, 1 H-NMR and 13 C-SSNMR were employed to qualitatively and quantitatively characterize the -OH and -C = C- groups in the methyl methacrylate (MMA) terminated PPO/TAIC co-cured system. No -OH groups were detected on the molecular chains of PPO oligomers, indicating that almost all the phenolic hydroxyl groups in the precursor had been substituted. During the curing, no new -OH groups were generated but some -C = C- groups were left unreacted. FTIR quantitative analysis showed that these -C = C- groups belonged to TAIC and the residual ratio of -C = C- could be as high as 60.37%.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 14
·2942
·
IF 4.6
Xinyu Gao,Jiahao Niu,Zhengjian Xiao,Da Rong,Mingming Yu,Sherwin K B Sy,Cong Wang,Zhihua Lv
Melatonin supplements have been widely used to improve sleep quality and overcome sleep disorders, with melatonin and vitamin B6 serving as the primary active ingredients. This study developed a novel analytical method for the simultaneous quantification of melatonin and vitamin B6 using 1 H-NMR spectroscopy. The characteristic signals of melatonin and vitamin B6 hydrochloride at δ 7.09 ppm and δ 8.12 ppm were selected for quantitative analysis, with maleic acid used as the internal standard. The method was validated for specificity, precision, and stability. The results demonstrate that the method exhibits high precision and complies with the guidelines established by the China Food and Drug Administration (CFDA). Furthermore, this method has been successfully applied to commercially available formulations. Compared to conventional methods, the 1 H-NMR technique offers a more efficient and simpler alternative, making it suitable for the simultaneous quantitative determination of melatonin and vitamin B6 hydrochloride. This approach ensures the quality, stability, and safety of commercial melatonin products.
研究领域:
分析化学
·
药物分析
·
核磁共振（NMR）谱学
·
质量控制
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DOI
PubMed
高影响因子
Current Pharmaceutical Analysis
·
2021
·Vol. 17
·期 4
·509-519
·
IF 0.89
Hou Zhuoni,Liang Zongsuo,Li Yuanyuan,Su Feng,Chen Jipeng,Zhang Xiaodan,Yang Dongfeng
Background: Although chromatography and spectrometry-based methods have been used to analyse phenolic acids in Chinese traditional medicine Salvia miltiorrhiza Bunge (SMB), quantitative nuclear magnetic resonance (qNMR) has never previously been used to analyse fresh SMB root extracts.
Objective: To establish a fast and simple method of quantitating danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B content in fresh SMB root using 1H-NMR spectroscopy. Method: Fresh SMB root was extracted using a 70% methanol aqueous solution and quantitatively
analysed for danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B using 1H-NMR spectroscopy. Different internal standards were compared and the results were validated using highperformance liquid chromatography. Results: The established method was accurate
and precise with good recovery. The LOD and LOQ indicated the excellent sensitivity of the method. The robustness was testified by the modification of four different parameters, and the differences among each parameter were all less than 2%. Conclusion: qNMR offers a fast, reliable, and accurate
method of identifying and quantifying danshensu, lithospermic acid, rosmarinic acid, and salvianolic acid B in fresh SMB root extracts.
研究领域:
生药学
·
分析化学
·
中医药
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DOI
高影响因子
CHEMICO-BIOLOGICAL INTERACTIONS
·
2014
·
IF 2.982
Zhaoguang Lu,Junsong Wang,Minghui Li,Qingwang Liu,Dandan Wei,Minghua Yang,Lingyi Kong
A goldfish ( Carassius auratus ) model of Parkinson’s disease (PD) was constructed by a single dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) according to previously reported methods. Global metabolite changes in brain of the MPTP induced goldfish model of PD were investigated. 1 H NMR-based metabolomics combined with various statistical methods such as orthogonal partial least squares discriminant analysis (OPLS-DA) and two-dimensional statistical total correlation spectroscopy (2D-STOCSY) found significant increase of leucine, isoleucine, valine, alanine, alanylalanine, creatinine, myo -inositol, 18:2 fatty acid, total fatty acids, arachic alcohol, taurine and significant decrease of N-acetylaspartate, (phospho)creatine, (phospho)choline, betaine, glutamine, 3-hexenedioate, acetamide, malonate, isocitrate, scyllo -inositol, phosphatidylcholines, cholesterols, n-3 fatty acids, polyunsaturated fatty acids (PUFAs) in brain of MPTP induced PD goldfish. These disturbed metabolite levels were involved in oxidative stress , energy failure, neuronal cell injury and death, consistent with those observed in clinical PD patients, and rodents and primates model of PD, indicating that the acute MPTP model of goldfish was an ideal and valuable model for PD research. In addition, several unusual metabolites in brain were significantly changed between MPTP induced PD and control goldfish, which might also play an important role in the pathogenesis of PD. This study also demonstrated the applicability and potential of 1 H NMR-based metabolomics approach for evaluation of animal models of disease induced by chemicals, such as MPTP-induced PD goldfish.
研究领域:
神经科学
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代谢组学
·
毒理学
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产品关联
DOI
PubMed
高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
·
IF 3.4
Mengyang Cai,Pengpeng Yang,Jinqiu Fu,Guiyu Chen,Keke Zhang
In this study, 19F solid-state nuclear magnetic resonance (ss-NMR) was applied to explore the effect of pore surface chemical environment on the molecular assembly of celecoxib. Celecoxib, which is hydrophobic, was encapsulated in mesoporous silica modified with different functional groups via the melt-cooling method. The results indicated that mesoporous silica modified with the different functional groups could enhance and regulate the dissolution rate of celecoxib. The 19F NMR results demonstrated that celecoxib molecules prefer to assemble into liquid-like molecular layers, when confined in the pores modified with hydrophilic functional groups. In contrast, celecoxib molecules embedded in mesoporous silica materials modified with hydrophobic functional groups tend to aggregate in the pore center, forming central amorphous plugs. When different functional groups are modified within the pores, the varying interactions with celecoxib result in different proportions of molecular aggregation states within the pores. Besides that, the dissolution performance of confined celecoxib molecules was determined by the molecular aggregation in the pores. This work uncovers the relationship between surface chemistry and molecular aggregation, which is fundamental to designing porous materials for drug release.
研究领域:
药剂学
·
材料科学
·
物理化学
·
核磁共振（NMR）光谱学
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产品关联
DOI
高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Moxia Li,Helei Liu,Xiao Luo,Paitoon Tontiwachwuthikul,Zhiwu Liang
In this work, three promising tertiary amines—1-(2-hydroxyethyl)piperidine (1-(2-HE)PP), 3-(diethylamino)-1,2-propanediol (DEA-1,2-PD), and N-(2-hydroxyethyl)pyrolidine (1-(2-HE)PRLD)—were experimentally studied and the results presented in terms of pKa, the protonation calibration curves, and ion speciation plots. The pKa of these amines were determined in the temperature range of 294–320 K. The protonation calibration curves for the three amines were also developed based on 13C NMR detection. In addition, ion (amine, amineH+, HCO3–, and CO32–) speciation plots for the three tertiary amines were developed at the temperature of 298 K, at the amine concentration of 1.0 M, over the CO2 loading ranges of 0–0.897 mol CO2/mol amine for 1-(2-HE)PP, 0–0.915 mol CO2/mol amine for DEA-1,2-PD, and 0–0.927 mol CO2/mol amine for 1-(2-HE)PRLD by using the pH method, the 13C NMR method, and the pH + 13C NMR method. By comparing the ion (amine, amineH+, HCO3–, and CO32–) concentrations of the three tertiary amines obtained from these three methods, it can be concluded that each of these three methods could be used to develop the ion speciation plots of amine–CO2–H2O systems, but there are some significant differences between them.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Mengdi Guo,Yumo Zhang,Zhibin Yi,Huo Li,Yang Liu,Liping Ding,Ganhui Huang,Jinsheng Zhang
Sensitive and accurate detection of harmful pathogenic bacteria in food is of great significance to public health. In this paper, a nuclear magnetic resonance (NMR) sensor based on biological signal amplification was constructed. The carboxymethyl dextran (CMD) was used as both the probe skeleton and the chelating agent to realize the fast chelating adsorption of the signal source gadolinium ion. Finally, the magnetic complex and biotinylated antibody formed an immune probe through the biological bridge to achieve rapid capture of Salmonella . In addition, non-target bacteria such as Proteus vulgaris and Listeria monocytogenes were used to test the specificity of the constructed sensor. The sensor can detect Salmonella within 1.5 h under optimal conditions, the detection limit in milk is 7.4 × 10 3 CFU mL −1 , and the RSD (Relative standard deviation) of reproducibility experiment is 2.35%, which has good reproducibility.
研究领域:
生物技术
·
食品科学
·
分析化学
·
微生物学
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产品关联
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 22
·3765
·
IF 2.972
Wei Liao,Wenqing Li,Zhenggang Fang,Chunhua Lu,Zhongzi Xu
Tobermorite and Al-substituted tobermorite with varying Al/(Si + Al) molar ratios were synthesized via the static hydrothermal method. The effect of different Al substitution ratios on the structure of tobermorite was investigated by XRD, SEM–EDS, TG–DSC, FT–IR,29Si, and27Al MAS–NMR. The interplanar crystal spacing of (002) increased with the increment of the Al substitution ratio. The maximum ratio of the Al substitution for Si in the structure of tobermorite was about 15 at %, which was limited by the compositions of tobermorite and the electrostatic repulsive forces caused by Al substitution. The DSC curve of the tobermorite with an Al/(Al + Si) molar ratio of 0.15 showed a larger exothermic peak area at 850 °C, indicating that the Al-O-Si bond was formed in the structure of tobermorite and the Al participated in the recrystallization. The29Si and27Al MAS–NMR results confirmed that tetrahedral Al was introduced into the structure of the tobermorite. New silicon sites, Q2(1Al) and Q3(1Al), formed by the Al substitution for Si in bridging and non-bridging sites, were detected. Compared to the tobermorite without Al substitution, the adsorption capacity of Al-substituted tobermorite with Al/(Al + Si) = 0.15 to Na+was improved by 44%.Keywords:hydrothermal synthesis;Al-substituted tobermorite;29Si MAS–NMR;27Al MAS–NMR;adsorption capacity
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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