RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2022
·Vol. 36
·期 23
·e9412
·
IF 2.586
Haifeng Zhuang,Lin Chen,Qiang Xu,Bingzhi Liu,Peiqi Liu,Zhandong Wang,Liangyuan Jia
Rationale Biomass is a potential feedstock for making liquid fuels and valuable chemicals. Quantitative analysis of biomass conversion in real time by photoionization mass spectrometry (PIMS) is an important way to understand the reaction process. However, the lack of photoionization data for biomass-derived compounds limits the research using PIMS. Methods Measurements of photoionization data were performed with synchrotron vacuum ultraviolet PIMS. Toluene and methanol were used as calibrated references and solvents in this experiment since their photoionization cross-sections (PICS) are well documented in the literature. Results The ionization energies (IEs) of 23 biomass-derived compounds were measured. Among them, the PICSs of 14 compounds were calibrated and presented. Besides, the IEs of 95 other biomass-derived compounds and their typical fragment ions were also summarized. Conclusions A photoionization database related to IEs and PICSs of biomass-derived compounds ( m / z < 200) is established. PICSs of most biomass-derived compounds have low values at the most frequently used photoionization energy of 10.5 eV. Lignin-derived compounds have lower IEs than carbohydrate-derived compounds.
研究领域:
能源科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
·
2011
·
IF 2.009
Mingfeng Xie,Zhongyue Zhou,Zhandong Wang,Dongna Chen,Fei Qi
The absolute photoionization cross-sections of 24 nitrogenous compounds were measured in the photon energy range from their respective ionization thresholds to 11.5 eV, including n -propylamine, iso -propylamine, n -butylamine, 2-butylamine, iso -butylamine, tert -butylamine, diethylamine, dibutylamine, triethylamine, aniline, benzylamine, n -methylaniline, cyclohexanamine, nitromethane, nitroethane, nitropropane, nitrobenzene, pyrrole, pyridine, pyrrolidine, morpholine, N , N -dimethylethanolamine, benzonitrile and benzeneacetonitrile. The experiments were performed by photoionization mass spectrometry with tunable synchrotron vacuum ultraviolet (VUV) light as an ionization source. Binary-liquid-mixtures of investigated and standard species were used in this measurement. As a good solvent, benzene was chosen as a calibration standard, since its photoionization cross-section had been well know. Moreover, photodissociative fragments were also presented.
研究领域:
化学
·
物理学
✓ 已验证
DOI
高影响因子
Analytical Methods
·
2024
·Vol. 16
·期 17
·2732-2739
·
IF 2.7
Shaoxin Ye,Zuoying Wen,Kai Xie,Xuejun Gu,Jian Wang,Xiaofeng Tang,Weijun Zhang
The growing popularity of e-cigarettes and the associated risks of nicotine addiction present a new challenge to global public health security. Measuring the nicotine levels in e-cigarette aerosols is essential to assess the safety of e-cigarettes. In this study, a rapid in situ method was developed for online quantification of nicotine in e-cigarette aerosols by using a homemade vacuum ultraviolet photoionization aerosol mass spectrometer (VUV-AMS). E-cigarette liquids with different nicotine concentrations were prepared to generate aerosols containing different levels of nicotine, which were employed as the calibration sources for nicotine quantification by VUV-AMS. The results showed that the mass concentration of nicotine in e-cigarette aerosols has a good linear relationship with its signal intensity in the mass spectrum, and the limits of detection and quantitation of nicotine by VUV-AMS were found to be 2.0 and 6.2 μg per puff respectively. Then the online method was utilized to measure five commercial e-cigarettes, and their nicotine yields were determined to be between 31 and 188 μg per puff with the nicotine fluxes from 7.7 to 70 μg s−1, agreeing with the results of the gas chromatography with a flame ionization detector (GC-FID). This study demonstrated the feasibility and advantages of VUV-AMS for quick quantification of nicotine in e-cigarette aerosols within seconds.
研究领域:
公共卫生
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Keke Qi,Yongmei Lv,Ying Xiong,Changlin Tian,Chengyuan Liu,Yang Pan
Laser-based high-resolution mass spectrometry imaging at ambient conditions has promising applications in life science. However, the ion yield during laser desorption/ablation is poor. Here, transmission atmospheric pressure laser desorption ionization combined with a compact postphotoionization (t-AP-LDI/PI) assembly with a krypton discharge lamp was developed for the untargeted imaging of various biomolecules. The spatial distributions of numerous lipid classes, fatty acids, neurotransmitters, and amino acids in the subregions of mouse cerebellum tissue were obtained. Compared with single laser ablation, the sensitivities for most analytes were increased by 1 to 3 orders of magnitude by dopant-assisted postphotoionization. After careful optimization, a spatial resolution of 4 μm could be achieved for the metabolites in mouse hippocampus tissue. Finally, the melanoma tissue slices were analyzed using t-AP-LDI/PI MSI, which revealed the metabolic heterogeneity of the melanoma microenvironment and exhibited the phenomenon of abnormal proliferation and invasion trends in tumor cells.
研究领域:
分析化学
·
生物医学
·
生命科学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Chenxin Wu,Yuxuan Wen,Lei Hua,Jichun Jiang,Yuanyuan Xie,Yixue Cao,Shuo Chai,Keyong Hou,Haiyang Li
Trimethylamine (TMA) is ubiquitous in the marine systems and may affect atmospheric chemistry as a precursor and strong stabilizer of atmospheric secondary aerosol, influencing cloud formation. Rapid and accurate measurement of the concentration of TMA in seawater is challenging due to their polarity, aqueous solubility, volatility and existence at low concentrations in marine environments. In this study, a dopant-assisted atmospheric pressure photoionization time-of-flight mass spectrometry (DA-APPI-TOFMS) coupled with a dynamic purge-release method was developed for rapid and sensitive analysis of TMA in seawater. A novel three-zones ionization source has been developed for improving the ionization efficiency of analyte molecules and minimizing the influence of high-humidity of the sample gas, which allowed direct analysis of high-humidity (RH> 90%) gas samples from microbubble purging process by the mass spectrometer . At atmospheric pressure, the three-zones ionization source allows the use of high-speed purge gas to quickly purge all organic amines dissolved in the water into the gas phase, ensuring quantitative accuracy. The limit of quantification (LOQ) for TMA down to 0.1 μg L −1 was obtained in less than 2 min by consuming only 2 mL seawater sample. This method was applied for the determination of the concentrations of TMA in the coastal seawater to validate its practicability and reliability for analysis of trace amines in marine environments.
研究领域:
海洋化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MASS SPECTROMETRY
·
2022
·Vol. 57
·期 3
·e4813
·
IF 2.394
Liutian Wu,Keke Qi,Minggao Xu,Chengyuan Liu,Yang Pan
Desorption electrospray ionization/post-photoionization (DESI/PI) is a newly developed ionization method by the combination of DESI and post-photoionization for the simultaneous imaging of polar and nonpolar compounds in biological tissues. Dopants are of great importance in DESI/PI for the enhancement of signal intensities through ion–molecule reactions. In this work, to evaluate the performance of dopants in DESI/PI, an efficient homogenate model was developed, and four kinds of dopants (toluene, chlorobenzene, bromobenzene, and anisole) were tested using homogenate of mouse brain tissue as target sample. The influences of the dopants on the signal enhancements of different compounds were explained reasonably by the ionization mechanism. Then, the dopants with their optimum volume contents were applied to the mass spectrometry imaging (MSI). For a comprehensive imaging of various compounds with different polarities, methanol/toluene/formic acid (7:3:0.1) was chosen as the best choice. Finally, the stronger quantitative ability of DESI/PI with toluene as dopant for a few compounds in mouse brain tissue was demonstrated.
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
ENERGY & FUELS
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2021
·
IF 3.605
Jiabin Huang,Xiaoqing Wu,Qifeng Hou,Mengqi Wu,Jiuzhong Yang,Feng Zhang
Near-threshold photoionization cross-section (PICS) is a key parameter for detecting and quantifying combustion intermediates in synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) experiments. In the present study, the PICSs of 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, o-cresol, m-cresol, p-cresol, anisole, and guaiacol were measured by PIMS. By collecting the PICSs of a series of monocyclic substituted aromatics (with hydrocarbon, oxygen-containing and nitrogen-containing substituents) measured in this work and those reported in literature, the similarity and difference of the PICSs of them is discussed from the view of molecular orbital analysis. It reveals that the frontier HOMO and HOMO–1 of these substituted benzene compounds mainly share the same characteristics with the degenerated HOMO of benzene. Nevertheless, the PICSs of benzene with hydrocarbon substituents are proportional to the photon energy after the threshold, while that of benzene presents a “plateau” region. The PICSs of substituted benzene where the substituents contain oxygen are more complicated than those with hydrocarbon substituents. For nitrogen-containing substituted benzene, cyano groups enhance the plateau characteristics of benzene, while the characteristics of amino-substituted benzene are similar to those of benzene with hydrocarbon substituents. The PICS data reported in this paper provide important parameters for SVUV-PIMS experiments. As a bridge between electronic structure and PICS, the molecular orbital analysis reveals the source of PICS characteristics of monocyclic substituted aromatic compounds.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Yongdi He,Jinou Song,Yuan Zhuang,Yongfeng Liu,Jibiao Xie
In order to investigate the effects of 1- nitropropane ( 1- NP) on the pyrolysis of n- hexane , the pyrolysis processes of pure n- hexane and n- hexane/ 1- NP mixture in a jet-stirred reactor (JSR) were experimentally studied at atmospheric pressure with the technique of synchrotron ultraviolet photoionization mass spectrometry (SVUV-PIMS). The pyrolysis experiments of pure n- hexane and n- hexane/ 1- NP mixture were performed in the temperature ranges of 673–1143 K and 598–1128 K, respectively. The species pools for the pyrolysis of pure n- hexane and n- hexane/ 1- NP mixture were comprehensively determined and 25 species for pyrolysis of pure n- hexane versus 18 species for pyrolysis of n- hexane/ 1- NP mixture were identified. Based on the photoionization mass spectra scanned at different photon energies, the mole fraction profiles of all the pyrolysis species were evaluated. The experimental results showed that the initial pyrolysis temperature of n- hexane was observably reduced by 75 K with the addition of 1- NP, and the initial formation temperatures (IFTs) of some major pyrolysis products and important intermediates were correspondingly reduced. A high degree of conformity in the species pools of the pyrolysis of pure n- hexane and n- hexane/ 1- NP mixture (at both low and atmospheric pressures) was observed. On the basis of the experimental observations, modeling simulations and mechanisms proposed in previous studies, the low-temperature mechanisms for the 1- NP-initiated pyrolysis of n- hexane were discussed. A mechanism, including unimolecular dissociation reactions of 1- NP, radical reactions to produce highly active radicals, H-abstraction reactions of n- hexane and subsequent C-C bond dissociation reactions of hexyl radicals, was proposed.
研究领域:
化学工程
·
燃料化学
·
环境科学
✓ 已验证
DOI
高影响因子
TALANTA
·
2016
·
IF 4.035
Zhen Li,Ce Xu,Jinian Shu,Bo Yang,Yao Zou
Real-time detection of lung cancer-related volatile organic compounds (VOCs) is a promising, non-intrusive technique for lung cancer (LC) prescreening. In this study, a novel method was designed to enhance the detection selectivity and sensitivity of LC-related polar VOCs by dichloromethane (CH 2 Cl 2 ) doping-assisted low-pressure photoionization mass spectrometry (LPPI-MS). Compared with conventional LPPI-MS, CH 2 Cl 2 doping-assisted LPPI-MS boosted the peak intensities of n -propanol, n -pentanal, acetone, and butyl acetate in nitrogen specifically by 53, 18, 16, and 43 times, respectively. The signal intensities of their daughter ions were inhibited or reduced. At relative humidity (RH) of 20%, the sensitivities of n -propanol, n -pentanal, acetone, and butyl acetate detection ranged from 116 to 452 counts/ppbv with a detection time of 10 s and R 2 >0.99 for the linear calibration curves . The method was also applicable under higher RH levels of 50% and 90%. Breath samples obtained from 10 volunteers and spiked samples were investigated. Eight-fold enhancements in the signal intensities of polar VOCs were observed in the normal and spiked samples. These preliminary results demonstrate the efficacy of the dichloromethane doping-assisted LPPI technique for the detection of LC-related polar VOCs. Further studies are indispensible to illustrating the detailed mechanism and applying the technique to breath diagnosis.
研究领域:
医学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Jinzeng Pan,Jinyu Tan,Shiling Wei,Shuyao Chen,Haikun Lang,Fangping Bin,Zhandong Wang,Lixia Wei
Isomers of alkanes have a significant effect on their combustion performance. In order to better understand the effect of the number of methyl side chains on fuel performance, the pyrolysis experiments of 2,3-dimethylhexane (C 8 H 18 –23) were carried out by using a jet-stirred reactor and the synchrotron vacuum ultraviolet photoionization mass spectrometry at 770 - 1130 K and at atmospheric pressure. Key pyrolysis products, such as acetylene, ethylene, propene, 1,3-butadiene, 2-butene, 1-pentene, 2-methyl-2-butene, 2-methyl-2-hexene, 3-methyl-2-hexene, as well as benzene, styrene and naphthalene, etc., were identified and measured. A detailed kinetic model of C 8 H 18 –23 pyrolysis, including 1756 species and 6023 reactions, was constructed and validated against the experimental results in the present work. Rate of production and sensitivity analysis of C 8 H 18 –23 showed that the major consumption pathways are H-abstractions and unimolecular dissociation reactions, with the highest contributions from those at/between C(2) and C(3) atoms. Theoretical comparison of the pyrolysis of the three isomers of C 8 H 18 hydrocarbon, i.e., C 8 H 18 –23, 2-methylheptane and n- octane, shows that with increasing of the number of methyl side chains, C 8 H 18 will be more reactive in pyrolysis and be more effective in producing soot precursors.
研究领域:
化学工程
·
燃料化学
·
燃烧科学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Hanyu Chen,Xi Wang,Yingwei Zhang,Yaoqi Hou
In a flow reactor, the pyrolysis process of n-pentane in the 450–750 °C temperature range was investigated at 760 Torr. The pyrolysis products, particularly free radicals and isomers, were identified using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry, and their mole fractions were determined. In this study, the existing n-pentane pyrolysis kinetic model was updated according to the C 5 -mechanism, and the new pyrolysis data were validated. The rate of production and sensitivity analyses were conducted to determine the significant reactions controlling the pyrolysis of fuel and their effects on the reactant concentration and product species profiles. The unimolecular decomposition reaction and free radical attack reaction via H attack dominate n-pentane pyrolysis at atmospheric pressure. Alkenes including 1-pentene, 1-butene, propene and ethylene are produced with higher concentrations than other product species in n-pentane pyrolysis.
研究领域:
化学动力学
·
燃料化学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Xuan Chen,Lei Hua,Jichun Jiang,Fan Hu,Ningbo Wan,Haiyang Li
High-pressure photoionization time-of-flight mass spectrometry (HPPI-TOFMS) is a versatile and highly sensitive analytical technique for online and real-time analysis of trace volatile organic compounds in complex mixtures. However, discrimination of isomers is usually a great challenge for the soft ionization method, and matrix effect is also inevitable under high pressure in the HPPI source. In this work, we describe a first attempt to develop a two-dimensional (2D) hyphenated instrument by coupling of a multi-capillary column (MCC) with a HPPI-TOFMS to overcome these problems. The capability of the MCC-HPPI-TOFMS for discrimination of isomeric compounds and elimination of the matrix effect was demonstrated by analyzing flavor mixtures. With the merits of fast separation, soft ionization and high detection sensitivity, satisfactory effects in the 2D analysis were achieved, despite the relatively low chromatographic resolution of MCC. As a result, three isomers, eucalyptol, l -menthone and linalool , in a flavor mixture were successfully categorized within 90 s, and the matrix effect caused by solvent ethanol was significantly eliminated as well. The limits of detection (LODs) down to sub-ppbv level were achieved for the investigated five flavor compounds without any enrichment process, and an excellent repeatability was obtained with the relative standard deviations (RSDs) of signal intensities ≤5%. The MCC-HPPI-TOFMS system was preliminarily applied for rapid and online analysis of flavor compounds in the exhaled gas of a volunteer after mouth rinsing with a gargle product. The rapid changes of the three flavor compounds, as well as the steady endogenous metabolite acetone, in the exhaled gas were successfully determined with a time-resolution of only 1.5 min.
研究领域:
分析化学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）