JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Hai-yan Liu,Zhi-yong Li,Dan Liu,Ying-Wen Xue,Zhi-guo Shi
Octadecyl bonded silica (ODS) is the most popular packing for reversed-phase chromatography. However, it generally demonstrates bad resolution for polar analytes because of the residue silanols and its poor stability in aqueous mobile phase. To address the problem, a new reversed-phase packing containing both polar-embedded and polar-endcapped moieties was proposed. It was prepared by a very simple method, in which the epoxide addition reaction of 3-glycidoxypropyltrimethoxysilane with 1-octadecanethiol proceeded simultaneously with the reaction of silane coupling onto silica particles. By controlling the molecular ratio of 3-glycidoxypropyltrimethoxysilane to 1-octadecanethiol higher than 1.0 (1.56 for the present study), both polar-embedded and polar-endcapped moieties were achieved onto the packing. The performance of the packing was evaluated in detail. The results demonstrated that neutral, acidic and basic analytes were well separated on the packing. The column efficiency for phenanthrene was 34,200 theoretical plates per meter. In addition, four nucleotides can be separated in 100% phosphate buffered saline solution with good reproducibility, which indicates the packing has good stability in aqueous mobile phase. Amitriptyline, a typical basic analytes, was eluted out with relatively symmetric peak shape (asymmetry factor of 1.36), which implies that the packing has not suffered from the negative effect of residue silanols significantly. Good stability in buffer solution of pH ranging from 2.0 to 10.0 was also documented for the packing.
研究领域:
分析化学
·
色谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2019
·
IF 5.128
Xiaohua Zhang,Hao Ma,Shubin Wu,Weikun Jiang,Weiqi Wei,Ming Lei
Great effort has been exerted to develop better, more effective fractionation techniques and improve the quality of bio-oil. Water extraction can be regarded as an effective method for bio-oil fractionation. In this study, fractionation of pyrolysis oil into water-soluble (WS) and water-insoluble (WI) phases by water extraction was investigated, and the influence of several factors, including water-to-oil ratio and water temperature, on the performance of the method were evaluated via several analytical techniques. When the water-to-oil ratio was 20:1 and the extraction temperature was 20 °C, polar and non-polar components were enriched in the WS (36.56 wt%) and WI (63.44 wt%) phases, respectively. Although extraction temperature had no significant effect on the properties of WS and WI, the distribution of polar and non-polar components was markedly affected by the dispersion and polarity of the compounds. 2D HSQC-NMR results revealed that side chain structures were more sensitive than aromatic structures to temperature. In view of these findings, an effective energy- and resource-saving extraction method featuring a water-to-oil ratio of 20:1 and extraction temperature of 20 °C is recommended for optimal water fractionation of pyrolysis oil.
研究领域:
能源生物学
·
分析化学
✓ 已验证
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2025
·
IF 6
Li Chen,Yibo Yan,Changbao Hong,Xiangting Wei,Jianhua Xiong,Chuixiu Huang,Xiantao Shen
Background Simultaneous determination of different natures of analytes is of great significance for saving sample volumes and simplifying analytical procedures. However, sample preparation for the simultaneous extraction of polar and non-polar analytes represents a challenge in sample preparation. Inspired by the successive liquid-phase microextraction (sLPME) method for acidic and basic analytes that we previously developed, we first proposed an efficient successive electromembrane extraction (sEME) system by adjusting the acidity of the donor solution and using binary organic solvents for extraction of polar and non-polar targets from biological samples in this work. Results We performed a detailed optimization of the sEME system. Here, carnitine (C0) and acylcarnitines were selected as model analytes since the demand increased especially in metabolomics studies. The combination of 2-nonanone and 2-nitrophenylpentyl ether (NPPE) was selected as supported liquid membranes (SLMs), and trichloroacetic acid (TCA) 100 % (v/v) was added to donor solution to adjust the acidity of the donor solution after the first sEME process (sEME-1). The recoveries of the targets in blood and urine were 47%–119% and 54%–118%, respectively. Moreover, the sEME systems were evaluated by liquid chromatography tandem mass spectrometry (LC-MS/MS) from biological samples. The limit of detection (LOD) and limit of quantitation (LOQ) of analytes were 0.03–1.33 ng mL −1 and 0.09–4.42 ng mL −1 , respectively. Significance sEME enabled the extraction of polar and non-polar analytes from the same sample under optimal extraction conditions for all target analytes, which provided ideas for efficient sEME of exogenous and endogenous analytes from biological samples for forensic, clinical, and epidemiological studies.
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2014
·
IF 3.511
Mingliang Zhang,Jia Chen,Tongnian Gu,Hongdeng Qiu,Shengxiang Jiang
Two new stationary phases modified by alkylimidazoliums were prepared for the first time and characterized. One of the new phases was obtained via monomeric immobilization of octadecylimidazole to γ-chloropropyltrimethoxysilane modified silica to form polar-embedded phase; the other one was prepared by co-immobilization of two silane coupling agents (γ-chloropropyltrichlorosilane and octadecyltrichlorosilane) to silica, followed by quaternization of methylimidazole to form polar-spaced phase. This study was intended to compare the retention characteristics of these two stationary phases using linear solvation energy relationships model, as well as to examine the difference in selectivity by eluting alkylbenzenes , alkylnaphthalenes, condensed-ring and phenylene polynuclear aromatic hydrocarbons on both phases. Different effects of distributions of polar functional group and octadecyl chain were found to impact the chromatographic properties.
研究领域:
分析化学
·
色谱技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Xiaoli Wu,Xingya Huang,Yongzheng Wang,Jingjing Chen,Ye Wan,Jianhua Liu,Wenpeng Li,Jingtao Wang
Two-dimensional (2D) lamellar membranes are favored over other membrane materials. However, the molecule transport behaviors in confined 2D nanochannels remain ambiguous, specifically the role of interlayer spacing which determines the confined effect. Herein, vertically-aligned nanochannel membranes with adjusted interlayer spacing (0.6 nm, 2.1 nm, and 3.9 nm) were fabricated by vermiculite lamellar membranes. These robust and long-range 2D nanochannels maintain stable molecule configuration state throughout the transport process, providing ideal platforms for investigating molecule transport behaviors. We demonstrate that molecules with weak molecule-molecule interactions (mainly nonpolar molecules) continuously collide with each other in the nanochannels. The extremely confined nanochannels (0.6 nm) restrict the random molecule collision and permit the oriented flow along transport direction, thus offering the highest transport efficiency. In contrast, molecules in wider nanochannels (3.9 nm) collide randomly, impairing the velocity of molecules or even compelling some of them to move to the adverse flow direction. This consumes cohesive energy and leads to lower permeance. The transport rate of benzene reaches over 130 L m -2 h -1 bar -1 nm -1 for 0.6 nm-nanochannel membrane, which is 8 times higher than that of 3.9 nm-nanochannel membrane. Compared to nonpolar molecules, the strong molecule-molecule and molecule-channel interactions for polar molecules would weaken this collision effect, thus the difference of transport rate is relatively small with nanochannel size.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
·
2018
·
IF 2.869
Bing Xia,Yuanji Gao,Baocheng Ji,Fengwei Ma,Lisheng Ding,Yan Zhou
Electrospray ionization mass spectrometry (ESI-MS) technique has limitations in analysis of compounds that are dissolved in nonpolar solvents. In this study, ambient ionization of compounds in solvents that are not “friendly” to electrospray ionization, such as n-hexane, is achieved by conductive nanomaterials spray ionization (CNMSI) on nanomaterial emitters, including carbon nanotubes paper and mesodendritic silver covered metal, which applies high voltages to emitters made of these materials without the assistance of polar solvents. Although the time intensity curves (TIC) commonly vary from 4.5% to 23.7% over analyses, protonated molecular ions were found to be the most abundant species, demonstrating good reproducibility of the technique in terms of ionized species. Higher mass spectrometric responses are observed in analyzing nonpolar systems than polar systems. 2-Methoxyacetophenone, 4-methylacetophenone, benzothiazole, quinolone, and cycloheptanone as low as 2 pg in n-hexane can be directly detected using the developed method. The developed technique expands the analysis capability of ESI-MS for direct, online analysis of nonpolar systems, such as low polarity extracts, normal phase liquid chromatography eluates, and synthetic mixtures.
研究领域:
分析化学
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纳米技术
·
质谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Shaobin Wen,Liyuan Fan,Yanqiu Wang,Tianheng Wang,Mengshi Chen,Qiang Zhang
A solvent-free photopolymerization method was employed to fabricate pervaporation membranes to separate polar/non-polar organic solvent mixtures. Commercially available monomers bis[2-(3,4-epoxy cyclohexyl)ethyl] tetramethyldisiloxane (TMDG) and 3,3'-(Oxybis(methylene))bis(3-ethyloxetane) (DOX), along with a photo-initiator, were mixed and spin-coated onto the PVDF membranes surface, followed by UV-curing to form polyether-polysiloxane coatings. This approach eliminates the use of organic solvents, offering a simple, efficient, and cost-effective process with significant economic and environmental benefits. Precise control over the coating structure and polarity was achieved by adjusting the monomer ratios. Among these composite membranes, M3 demonstrated excellent permeability and separation efficacy for the pervaporation of polar/non-polar mixed organic solvents. At 45 °C, the flux of M3 to acetone/n-hexane (5 wt %/95 wt %) and methanol/n-hexane (5 wt %/95 wt %) were 615 and 559 g m −2 h −1 , respectively, and the separation factors were 836 and 798, respectively. Moreover, M3 also exhibited an excellent separation effect on acetone / n-hexane azeotropes (59 wt % / 41 wt %, 49.8 °C), with a flux of 1806 g m −2 h −1 and a separation factor of 121. Ultimately, M3 maintained stable permeability and separation performance for acetone/n-hexane (5 wt %/95 wt %) throughout 168 h, demonstrating the outstanding chemical stability of the coating prepared by UV-curing.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2017
·
IF 3.177
Yanyu Qi,Rui Kang,Jie Huang,Weidong Zhang,Gang He,Shiwei Yin,Yu Fang
We demonstrated for the first time that, at temperatures below the melting point of a given polar solvent, the emission of some four-coordinate monoboron complexes containing monoanionic bidentate (NO) ligands shifted to lower wavelengths, but no such shift was observed for studies conducted in nonpolar solvents. This means that the emission from a polar solvent appears at shorter wavelengths if compared with that from a nonpolar solvent when the measurement was performed at low temperatures, a phenomenon totally different from that observed for conventional solvatochromic fluorophores. The finding was rationalized by considering the temperature-dependent conformational relaxation of the tetrahedron monoboron complexes from their local excited (LE) state to their relaxed excited (RE) state. Further studies revealed that variating the structure of the chelating ligands could result in remarkable changes in the fluorescent colors of the monoboron complexes. However, changing the structure of other two monodentate ligands showed little effect upon the fluorescence property of the compounds. Therefore, it is anticipated that the monoboron complexes may be taken as a platform to construct a variety of functional molecular systems via alternating the structure of the chelating ligand and that of the monodentate ligand. As an example, naphthalene was introduced as a monodentate ligand, and independent emissions from naphthalene unit and the other part of the monoboron complex as well as intramolecular energy transfer between them were observed. It is believed that the present work provides a new insight into the monoboron complexes, laying the foundation for them to be explored for developing novel molecular systems.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Luze He,Shuang Pan,Zhiqun Lin,Juan Peng
Despite recent impressive advances in the synthesis of all-inorganic perovskite CsPbX3 (X = Cl, Br, and I) via facile solution-based approaches, it remains challenging to achieve well-defined morphologies of interest, particularly one-dimensional (1D) nanowires. Herein, we report a robust polar-solvent-assisted route to 1D CsPbBr3 nanowires via room temperature supersaturated recrystallization. Notably, compared to CsPbBr3 nanocubes synthesized in the absence of polar solvent acetonitrile (ACN), upon the introduction of a suitable amount of ACN into antisolvent toluene, CsPbBr3 nanowires are rapidly yielded, experiencing a cubic-to-orthorhombic phase transformation and a blue-shifted emission. The formation mechanism of CsPbBr3 nanowires can be qualitatively understood on the basis of the role of ACN as a structure-directing agent. Intriguingly, the addition of ACN renders an accelerated anion-exchange reaction between CsPbBr3 and halide salts (i.e., Br-to-Cl and Br-to-I exchanges) due to improved dissolution of the halide ions in ACN. The polar solvent-directed growth strategy may represent an effective means of expanding the diversity of morphologies accessible to perovskite nanocrystals. As such, it facilitates an investigation into the dimension-dependent optical and optoelectronic properties of perovskite-based nanomaterials and devices. These CsPbBr3 nanowires can be potentially used for nanoscale photonic, electronic, and optoelectronic devices, including photodetectors, light-emitting diodes, lasers, and solar cells.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
DOI
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Cheng Yang,Haijun Yan,Qianhe Huang,Wenge Yang,Yonghong Hu
Esculetin is derived from the leaves of lemons of Rutaceae and the bark of bittersweet ash, belladonna, mandala, and Rehmannia plants. In this research, the solubility of esculetin in ten solvents such as ethyl acetate, isobutyl alcohol, water, methanol, acetonitrile, n-propyl alcohol, isopropyl alcohol, n-butanol, ethanol, and acetone was determined by utilizing static equilibrium-high performance liquid chromatography (HPLC) under standard atmospheric pressure conditions and temperatures in the range of 273.15 to 318.15 K. Among the above ten pure solvents, water displayed the least solubility, while methanol exhibited the highest solubility. At the same temperature (T = 273.15 ∼ 318.15 K), the solubility of esculetin increased with the increase of the molar ratio of soluble solvents. Similarly, when the temperature increases (T = 273.15 ∼ 318.15 K), the solubility of the three binary solvents increases under the condition of a constant molar ratio. The above results suggest that the main factor affecting the solubility of esculetin in the solvent may be the polarization/bipolarity of the solvent. The experimental data was fitted by five thermodynamic models (the Buchowski–Ksiazaczak λh model, the Modified Apelblat model, the Jouyban–Acree model, the SUN model, and the CNIBS/R-K model), and the relative average deviation and root-mean-square deviation of the data were calculated, which proved that the correlation of the solubility data and the five models was relatively good. XRD and DSC were used to detect the crystal form and stability of esculetin during the experiment.
研究领域:
药学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2025
·
IF 10.5
Yue Huang,Yang Liu,Chuan Dong,Qi Zan,Feng Feng,Ruibing Wang,Shaomin Shuang
Mitophagy is a key pathway for regulating mitochondrial quality and quantity which is essential for the preservation of cellular homeostasis. Mitophagy process may be accompanied by changes of the mitochondrial microenvironments. The multifunctional fluorescent probe is crucial for the precise detection of multiple microenvironments, which is vital for the visualization of mitophagy. Herein, a mitochondria-immobilized fluorescent probe DPP was designed and fabricated to visualize mitophagy by monitoring polarity and viscosity in dual-channel. The DPP is characterized by "D-π-A" structure, which provides the basis for the intramolecular charge transfer (ICT) and twisted intramolecular charge transfer (TICT) platform, enabling dual-channel responses to polarity and viscosity at emission wavelengths of 487 nm and 656 nm, respectively. The significant wavelength gap (169 nm) between the above channels prevents signal crosstalk. Additionally, the incorporation of 1, 4-dibenzyl chloride grants the probe mitochondrial immobilization capabilities, avoiding the leak of probe due to mitochondrial depolarization during autophagy. The DPP accumulates in mitochondria and monitors polarity and viscosity changes in green and red channels, respectively. Notably, the investigation of the relationship between polarity and viscosity revealed that an increase in viscosity is accompanied by a decrease in polarity. The mitophagy was effectively observed through the induction of DPP by rapamycin, with a particular emphasis on the increase in viscosity and decrease in polarity. Thus, DPP offers a powerful tool for a deeper understanding of the physiological and pathological processes associated with mitophagy and are regulated by various microenvironmental parameters.
研究领域:
细胞生物学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 27
·18455-18462
·
IF 3.906
Xiangyang Duan,Chao Ma,Wentao Jin,Xiaoman Ma,Lu’an Guo,Su-Huai Wei,Jinying Yu,Yelong Wu
A simple and efficient top-down strategy, the chemical vapor etching method, is reported for synthesizing corrugated ZnO nano/micro rods (NRs). The stabilization mechanism of this unique nanostructure has been determined through a combination of aberration-corrected field emission scanning electron microscopy, high-resolution transmission electron microscopy, and first-principles calculations. The experimental data are in good agreement with the theoretical calculations, and a remarkable nonpolar-to-polar surface faceting transition is demonstrated. The corrugated-shaped structure results from the remarkable stability of the defect-induced reconstructions (O vacancy, Zn–Zn dimer), which makes the high-index polar {301} and {10} planes lower in energy compared to the nonpolar {100} plane. Based on the results of first-principles surface calculations, a general formula is established to provide an accurate description of the unusual size effect of the length of the corrugated unit vs. the NR diameter, and it also offers direct explanations for certain experimental observations. The present study deepens our atomic-level understanding of the detailed structure and stability of polar surface decorated corrugated ZnO NRs, and points to a viable path towards designing polar-stable wurtzite structures.
研究领域:
材料科学
·
纳米科技
·
表面科学
·
凝聚态物理
·
计算材料学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）