Frontiers in Chemistry
·
2022
·
IF 5.545
Liu Qian-Bao,Lu Jing-Guang,Jiang Zhi-Hong,Zhang Wei,Li Wen-Jia,Qian Zheng-Ming,Bai Li-Ping
Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a sensitive surface analytical technology, which can simultaneously acquire diverse chemical components and their precise locations on the surfaces of samples without any requirements for chemical damage pretreatments or additional matrices. Commonly, the quality control of TCMs (traditional Chinese medicines) is limited by the qualitative and quantitative evaluations of the specifically extractive constituents. In this study, a practical sample preparation strategy named two-layered media embedding sample preparation was developed to obtain ideal freezing sections of dried materials of Cordyceps sinensis. Meanwhile, the well-established sample preparation method was applied for in situ chemical profiling and imaging of natural (NCS) and cultured Cordyceps sinensis (CCS) by using TOF-SIMS. More than 200 components were tentatively identified and imaged in NCS and CCS at the same time. Mass spectrometry imaging revealed that most components have even distributions in caterpillars of Cordyceps sinensis, while TAGs, DAGs, MAGs, and FAs only have distributions outside caterpillars’ digestive chambers. This is the first time that components were in situ imaged for Cordyceps sinensis to exhibit the chemical distributions which have never been achieved by other analytical techniques so far. In addition, chemometrics was used to simplify and explain the massive TOF-SIMS mass data sets, which revealed the high chemical similarity between CCS and NCS. Furthermore, the relative quantification of TOF-SIMS data showed that CCS has comparable proportions of amino acids, nucleosides, monosaccharides, sphingolipids, sterols and other principles to NCS except for fatty acids, glycerides and glycerophospholipids. The higher amounts of TAGs and DAGs in CCS were confirmed by quantitative 1H-NMR, indicating reliable relative quantification of TOF-SIMS. In general, our research developed a novel approach of TOF-SIMS for in situ chemical analysis of TCMs, and its successful application in comparative study of CCS and NCS suggested that TOF-SIMS is an advanced and promising analytical technology for the research of TCMs.
研究领域:
分析化学
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中药学
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生物化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2025
·
IF 11.3
Hailan Wang,Ruobin Dai,Zhiwei Wang
Deciphering the structure and composition of the scaling layer is crucial for understanding its formation mechanisms in the reverse osmosis (RO) process. However, conventional characterization techniques face challenges in providing high three-dimensional resolution and precise compositional analysis of mixed scales, which hinders in-depth elucidation of the underlying mechanisms. In this study, we combined the exceptional depth resolution of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the superior mixed-scale discrimination capability of thermogravimetry-infrared spectroscopy (TG-IR) to analyze Si/Al scaling, a common issue in industrial RO systems. Under acid conditions, ToF-SIMS measurements revealed Al species enrichment on the membrane surface, attributed to the strong affinity between Al3+ and the membrane. The preferential deposition of Al3+ further facilitated the heterogeneous nucleation of polymerized silica through the electrostatic shielding effect, leading to the rapid formation of a thin and dense scaling layer. In contrast, neutral and alkaline conditions produced a slower-developing, uniform, thicker, and loosely structured scaling layer through physical deposition of supersaturated Si/Al complex scales. TG-IR analysis revealed that neutral conditions favored coprecipitated adsorption-bound Si/Al species (6-coordinate Al) and Si/Al polymers (4-coordinate Al), whereas alkaline conditions primarily produced coprecipitated silica and Al(OH)4−. These findings advance the mechanistic understanding of Si/Al scaling and provide a foundation for targeted control strategies in silica-metal combined scaling in RO systems.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2019
·Vol. 411
·期 18
·4025-4030
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IF 3.286
Li Hao-Wen,Hua Xin,Long Yi-Tao
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has shown promising applications in single-cell analysis owing to its high spatial resolution molecular imaging capability. One of the main drawbacks hindering progress in this field is the relatively low ionization efficiency for biological systems. The complex chemical micro-environment in single cells typically causes severe matrix effects, leading to significant signal suppression of biomolecules. In this work, we investigated the signal enhancement effect of graphene quantum dots (GE QDs) in ToF-SIMS analysis. A × 160 magnification of ToF-SIMS signal for amiodarone casted on glass slide was observed by adding amino-functionalized GE QDs (amino-GE QDs), which was significantly higher than adding previously reported signal enhancement materials and hydroxyl group-functionalized GE QDs (hydroxyl-GE QDs). A possible mechanism for GE QD-induced signal enhancement was proposed. Further, effects of amino-GE QDs and hydroxyl-GE QDs on amiodarone-treated breast cancer cells were compared. A significant signal improvement for lipids and amiodarone was achieved using both types of GE QDs, especially for amino-GE QDs. In addition, ToF-SIMS chemical mapping of single cells with better quality was obtained after signal enhancement. Our strategy for effective ToF-SIMS signal enhancement holds great potential for further investigation of drug metabolism pathways and the interactions between the cell and micro-environment.
研究领域:
分析化学
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生物医学工程
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材料科学
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细胞生物学
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药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION SCIENCE
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2025
·
IF 8.5
Z.N. Jiang,J.M. Duan,S.Y. Tian,R.Y. Xue,C.F. Dong,G.A. Zhang
A green corrosion inhibitor, (2 E , 4 E )-2-cyano-5-phenyl-2,4-pentadienoic acid (CPPA), was synthesized via one-step modification of cinnamaldehyde. CPPA exhibits outstanding inhibition effect for mild steel (MS) in HCl medium with an inhibition efficiency of 98.83 % at a concentration of 0.6 mM with good inhibition stability. The inhibition mechanism of CPPA was elucidated by combining surface characterization techniques with ab initio molecular dynamics (AIMD) simulations. XPS and ToF-SIMS analyses indicate that CPPA molecules could adsorb on MS surface by covalent bonding through N, C, and O atoms. AIMD simulations reveal that CPPA approaches to steel surface motivated by van der Waals force, i.e., physisorption occurs. Subsequently, the physisorption of CPPA is transformed into a strong and stable chemisorption, which was demonstrated by IGMH, CPPA-Fe bond length, electron density difference and PDOS characteristics. The adsorbed CPPA film significantly improves the hydrophobicity of MS surface, and acts as a shield to effectively hinder the diffusion and access of corrosive particles to steel surface, thus exhibiting outstanding and stable corrosion inhibition performance.
研究领域:
材料科学
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腐蚀工程
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表面化学
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计算化学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2018
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IF 3.789
Xiaopeng Niu,Renman Ruan,Liuyin Xia,Li Li,Heyun Sun,Yan Jia,Qiaoyi Tan
When it comes to Pb–Zn ores with high amounts of pyrite, the major problem encountered is the low separation efficiency between galena and pyrite. By virtue of high dosage of lime and collector sodium diethyl dithiocarbamate (DDTC), pyrite and zinc minerals are depressed, allowing the galena to be floated. However, there have been significant conflicting reports on the flotation behavior of galena at high pH. In this context, correlation of the surface adsorption and oxidation with the floatability difference of galena and pyrite in high-alkaline lime systems would be a key issue for process optimization. Captive bubble contact angle measurements were performed on freshly polished mineral surfaces in situ exposed to lime solutions of varying pH as a function of immersion time. Furthermore, single mineral microflotation tests were conducted. Both tests indicated that the degree of hydrophobicity on the surfaces of galena and pyrite increased in the presence of DDTC at natural or mild pulp pH. While in a saturated lime solution, at pH 12.5, DDTC only worked for galena, but not for pyrite. Surface chemistry analysis by time-of-flight secondary ion mass spectrometry (Tof-SIMS) confirmed the preference of DDTC on the galena surface at pH 12.5, which contributed to a merit recovery. Further important evidence through measurements of Tof-SIMS, ion chromatography, and high-performance liquid chromatography indicated that in high-alkaline lime systems, the merit floatability of galena could exclude the insignificant contribution of elemental sulfur (S8) and was dominantly attributed by the strong adsorption of DDTC. In contrast, the poor flotation response of pyrite at high pH was due to the prevailing adsorption of CaOH+ species. This study provides an important surface chemistry evidence for a better understanding of the mechanism on the better selectivity in the galena–pyrite separation adopting high-alkaline lime systems.
研究领域:
矿物加工
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表面化学
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浮选技术
✓ 已验证
DOI
PubMed
高影响因子
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