FUEL
·
2019
·
IF 5.128
Xiu Chen,Haidong Li,Linzhou Zhang,Quan Shi,Suoqi Zhao,Chunming Xu
In the present paper, the molecular composition of sulfidic and thiophenic compounds in petroleum samples were selectively characterized by positive-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) after cyclohexanone peroxide (CYHPO) oxidation followed by methylation . The sulfidic compounds in petroleum were mainly oxidized to sulfones by CYHPO while most of thiophenic compounds were not reacted. In the followed methylation process, the unreacted thiophenic compounds were converted to methylsulfonium. After using ammonium formate (HCOONH 4 ) as a promoter, the obtained sulfidic sulfones (O 2 S 1 class species) were selectively ionized in the form of N 1 O 2 S 1 class species under positive-ion ESI FT-ICR MS. The thiophenic methylsulfonium salts in the oxidation-methylation products were also identified by positive-ion ESI FT-ICR MS as S 1 class species. This analytical scheme was evaluated by a variety of model compounds and then applied successfully to diesel, VGO and crude oil samples to obtain the molecular composition of sulfidic and thiophenic compounds. In addition, the molecular type of biomarkers and other compounds in petroleum samples can be identified by this analytical scheme.
研究领域:
分析化学
·
石油化学
✓ 已验证
DOI
高影响因子
Science China-Chemistry
·
2013
·Vol. 56
·期 7
·863-873
·
IF 1.327
Wang LiTao,He Chen,Liu Yang,Zhao SuoQi,Zhang YaHe,Xu ChunMing,Chung Keng H.,Shi Quan
A vacuum topped Canadian oilsands bitumen (VTB) was subjected to solvent precipitation and subsequently characterized by elemental analysis, gel permeation chromatograph (GPC), 1 H-NMR spectroscopy and negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Effects of experimental conditions such as solvent types ( n -C 5 , n -C 6 , and n -C 7 ), solvent purity, and solvent washing time on asphaltenes yields, bulk composition, and molecular composition of detectable heteroatom compounds in ESI source were determined. Elemental nitrogen and sulfur were enriched in asphaltenes while elemental oxygen had comparable content in maltenes and asphaltenes. Molecular composition of asphaltenes varies with separation conditions. The N 1 and O 1 species identified by ESI FT-ICR MS were enriched in maltenes. The O 2 species exhibited two different double bond equivalents (DBE) distributions and solubility in normal paraffin solvents, indicating two types of molecular structures. Multi oxygen atom containing compounds mainly detected in asphaltenes. Compound class distributions are similar for maltenes derived from n -C 5 , n -C 6 , and n -C 7 , as well as for asphaltenes. The cyclic paraffin impurities in normal paraffin solvents had a significant influence on asphaltenes yields and heteroatom molecular composition. A portion of neutral N 1 species and acidic O 2 species adsorbed on asphaltenes could be dissolved by increasing washing time. Cautions should be exercised when interpreting the properties and composition of asphaltenes obtained with different experimental conditions.
研究领域:
石油化学
·
分析化学
✓ 已验证
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Xiu Chen,Haidong Li,Linzhou Zhang,Quan Shi,Suoqi Zhao,Chunming Xu
Molecular-level characterization of sulfur-containing compounds has attracted particular attention due to its relative high abundance and negative impact on the refining process. In this paper, a novel analytical method for selective ionization of sulfidic and/or isolated thiophenic compounds (thiophene rings that are not condensed with aromatic systems) and condensed thiophenic compounds (thiophene rings that are condensed with aromatic systems, DBE ≥ 6, DBE = number of rings plus double bonds to carbon) in petroleum samples was developed by using fluoroboric acid (HBF 4 ) as ionization promoter. Positive-ion electrospray ionization [(+) ESI] Fourier transform ion cyclotron resonance mass spectrometry was followed to characterize the molecular composition. Sulfidic and/or isolated thiophenic compounds were mainly ionized as protonated molecular ions ([M+H] + ), while condensed thiophenic compounds (DBE ≥ 6) were mainly ionized as molecular radical cations (M + ). The method was validated by various sulfur-containing model compounds and then applied to vacuum gas oil, crude oil and heavy oil samples. (+) ESI coupled with HBF 4 additive is a simple method for selective ionization of sulfides and thiophenes in high-sulfur-content petroleum samples and has the potential for the characterization of sulfides and thiophenes in other complex mixtures.
研究领域:
化学
·
能源科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2023
·Vol. 10
·期 5
·1220-1231
·
IF 7.3
Shishu Zhu,Yijun Mo,Wendan Luo,Zihan Xiao,Chao Jin,Rongliang Qiu
Soil dissolved organic matter (SDOM) forms the corona and affects the colloidal mobility of Cr (hydr)oxides. Such processes are important in evaluating Cr immobilization effectiveness. This study for the first time found that the SDOM composition instead of electrostatic interactions accounted for the significant differences in the aggregation and deposition kinetics of short-range-order Cr(OH)3 Cr(OH)3 and crystalline Cr2O3. The molecular-scale composition of SDOM associated with Cr (hydr)oxides was investigated using Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) and Fourier transform-infrared spectroscopy (FT-IR). Low molecular-weight aromatic compounds with multiple carboxyl groups and amphiphilic segments preferentially associated with Cr(OH)3, whereas Cr2O3 mainly adsorbed high molecular-weight hydrophobic compounds. The molecular composition of SDOM associated with colloids depended on the singly coordinated hydroxyl content of Cr (hydr)oxides. The aggregation and deposition of Cr(OH)3 significantly increased with increasing SDOM loading due to the formation of more thermodynamically stable coprecipitates in solution or on the silica surface via bridging of carboxylates. A secondary zonal layer on Cr(OH)3 inhibited the coprecipitation of Cr(OH)3 with SDOM under a high SDOM loading. In contrast, the aggregation and deposition of Cr2O3 decreased with increasing SDOM loading due to the steric hindrance of hydrophobic compounds. This study highlighted the importance of corona composition in assessing the potential mobility of Cr (hydr)oxides and the stability of immobilized Cr species.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xuanyu Ji,Alberto Tiraferri,Xiaofei Zhang,Peng Liu,Zhiwei Gan,John C. Crittenden,Jun Ma,Baicang Liu
Knowledge on the composition and characteristics of dissolved organic matter (DOM) in complex shale gas wastewater (SGW) is critical to evaluate environmental risks and to determine effective management strategies. Herein, five SGW samples from four key shale gas blocks in the Sichuan Basin, China, were comprehensively characterized. Specifically, FT-ICR MS was employed to provide insights into the sources, composition, and characteristics of SGW DOM. Organic matter was characterized by low average molecular weight , high saturation degree, and low aromaticity. Notably, the absence of correlations between molecular-level parameters and spectral indexes might be attributed to the high complexity and variability of SGW. The unique distribution depicted in van Krevelen diagrams suggested various sources of DOM in SGW, such as microbially derived organics in shales and biochemical transformations. Moreover, linear alkyl benzene sulfonates , as well as associated biodegraded metabolites and coproducts, were identified in SGW, implying the distinct anthropogenic imprints and abundant microbial activities . Furthermore, high DOC removal rates (31.42–79.23 %) were achieved by biological treatment, fully supporting the inherently labile nature of SGW and the feasibility of biodegradation for SGW management . Therefore, we conclude that DOM in SGW is a complex but mostly labile mixture reflecting both autochthonous and anthropogenic sources .
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
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