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1.
Muller H Adam FM Panda SK Al-Jawad HH Al-Hajji AA 《Journal of the American Society for Mass Spectrometry》2012,23(5):806-815
Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been applied for the quantitative speciation of
sulfur containing compounds in gas oil (GO). For this purpose, ionization and mass spectrometric parameters have been studied
and optimized with a set of standard compounds and GO samples. Comprehensive two-dimensional gas chromatography (GCxGC) was
used as the reference method. To allow a quantitative comparison between FT-ICR MS and GCxGC results for GO samples, FT-ICR
MS parameters were optimized and data obtained by both techniques were standardized. Response factors were established for
two ionization modes: atmospheric pressure photo ionization (APPI) and electrospray after selective derivatization of sulfur
compounds (MeESI). To test the validity of the developed MS methods, a third GO was analyzed and response factors were applied.
Comparison with GCxGC results showed good agreement for sulfur families (deviation within 5% and 15% for MeESI and APPI data,
respectively). Abundances of individual isomer groups match within 40% in most cases. These results principally demonstrate
the suitability of FT-ICR MS for a quantitative analysis of sulfur compounds (by DBE and carbon number distribution pattern)
in petroleum middle distillates. This approach has the potential to be extended to higher- and non-boiling petroleum fractions
where quantitative speciation is presently not available. 相似文献
2.
Simone Schiesel Michael Lämmerhofer Wolfgang Lindner 《Analytical and bioanalytical chemistry》2010,396(5):1655-1679
The presented work deals with the development and comprehensive validation of a quantitative LC–electrospray ionization (ESI)–tandem
mass spectrometry (MS/MS) method using a triple quadrupole instrument in the MRM mode for the metabolic profiling of amino
acids, organic acids, vitamins, some biogenic amines, secondary metabolites of β-lactam antibiotics biosynthesis as well as
their intermediates, and degradation products in fermentation broths of β-lactam antibiotics production (in total 57 hydrophilic
compounds). A great number of chromatographic systems (22 different stationary phase/mobile phase conditions) were screened
for their adequate chromatographic selectivity to cope with isobaric compounds and other critical analyte pairs. Finally,
a hydrophilic interaction liquid chromatography (HILIC) method employing a zwitterionic ZIC-HILIC column was selected as best
compromise. Particular focus was given on the elucidation of absolute and relative matrix effects via comparison of slopes
of calibration functions of spiked matrix and standard solutions. These data as well as precision and accuracy data confirm
suitability of the HILIC–ESI–MS/MS assay for metabolic profiling studies in fermentation samples. Detailed comprehensive data
sets are presented which should illustrate critical issues, problems, and challenges of multitarget quantitative metabolic
profiling and should outline possible strategies to circumvent pitfalls and overcome common problems. 相似文献
3.
在四氟硼酸银的催化作用下,以碘甲烷对直馏柴油进行甲基衍生化反应,使其中的有机硫化物转变成极性较强的锍盐,再用电喷雾-傅立叶变换离子回旋共振质谱仪进行检测。结合气相色谱-脉冲火焰光度检测器(GC-PFPD)分析,研究不同类型的硫化物甲基衍生化反应的选择性和转化率。结果表明:柴油中硫化物在室温条件下容易与碘甲烷发生甲基化反应,大部分硫化物转化为锍盐,总转化率超过80%,苯并噻吩类比二苯并噻吩类更易发生甲基衍生化反应,转化率也相应较高。烷基二苯并噻吩不同取代位异构体间反应选择性存在较大差异,高分辨质谱分析结果表明,直馏柴油中存在环状硫醚类化合物。 相似文献
4.
J. García-Lavandeira C. Salgado-Petinal E. Blanco R. Cela 《Analytical and bioanalytical chemistry》2010,397(2):751-763
We have developed and validated a quantitative liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI
MS/MS) procedure for the simultaneous determination of seven natural and semisynthetic tropane alkaloids in plasma: atropine
(d-hyoscyamine/l-hyoscyamine), cocaine, homatropine, ipratropium, littorine, N-butylscopolamine, and scopolamine. Plasma and serum samples were precipitated for deproteinization (recovery 88–94%), followed
by reversed-phase-based liquid chromatography prior to positive electrospray ionization for detection by multiple reaction
monitoring using a linear ion trap quadrupole mass spectrometer. All analytes were quantified using cocaine-d3 as an internal standard suitable and reliable for robust, precise (coefficient of variation 2–13%), and accurate (87–122%)
measurement within a linear range of 3 orders of magnitude (0.05–50 ng/ml plasma). The method was exemplarily applied to stability
studies in phosphate-buffered saline, human serum, and rabbit serum. Each alkaloid was incubated separately and samples were
taken at distinct incubation time points. Supernatants of diverse alkaloids at corresponding time points were pooled and subjected
to simultaneous LC-ESI MS/MS quantification. This combinatorial analysis design allowed us to analyze the stability of samples
with a drastically reduced number of chromatographic runs. In the presence of rabbit serum, all tropane alkaloids tested were
degraded significantly within minutes to hours, with the exception of the stable semisynthetic compounds ipratropium and N-butylscopolamine. In contrast, in the presence of equal concentrations of human serum, no degradation was observed for any
of the compounds, with the exception of cocaine. Relevant enzymes involved in enzymatic degradation are discussed. 相似文献
5.
Yu. S. Nekrasov N. S. Ikonnikov Yu. A. Belousov S. S. Kiselev 《Journal of Analytical Chemistry》2011,66(13):1291-1297
We have studied the behavior of ferrocene CpFeCp (FcH), ferrocenium triiodide [FcH]+I3−, dimethylaminomethylferrocene FcCH2NMe2 and its trimethylammonium salt [FcCH2NMe3]+I− under the conventional conditions of electrospray ionization (ESI), when the substance solution is subjected to spraying,
and in two versions of desorption electrospray ionization (DESI), when the sprayed solvent bombards the surface of solid or
liquid samples. In addition to these techniques, the behavior of neutral compounds under conditions of electrospray ionization
of vapors of the studied compounds in a gas phase (ESI_V) has been investigated. It has been shown using the examples of ferrocene
and its dimethylaminomethyl derivative that the detection limits for these compounds occurring in a gas phase are comparable
within an order of magnitude with their detection limits under the ESI and DESI conditions of solid and liquid samples. The
high effectiveness of ionization of analyte vapors makes it possible to use the ESI method not only in combination with liquid
(conventional ESI technology) and thin layer chromatography (DESI), but also with gas liquid chromatography (ESI_V). Thus,
the electrospray ionization becomes a universal method allowing studies of a compound under the natural conditions in any
state of aggregation, that is, solid, liquid, and gas. With the help of statistical methods for designing experiments (complete
factorial experiment), quantitative evaluation of the influence of experimental parameters on the ion-formation processes
under different ESI conditions has been carried out, which makes it possible to purposefully select the optimal conditions
to record the ESI mass spectra with a minimum number of experiments. Moreover, analysis of the dependences of the mass spectra
on the experimental parameters can serve as an instrument for studying the details of the ion-formation mechanisms depending
upon different ways of ionization. 相似文献
6.
Zhang J Dong X Cheng J Li J Wang Y 《Journal of the American Society for Mass Spectrometry》2011,22(7):1294-1298
In this Application Note, we describe, for the first time, the rapid analysis of hydrophobic compounds present in environmental
contaminants, which includes polycyclic aromatic hydrocarbons (PAHs) and estrogen, by matrix-assisted laser desorption/ionization
time-of-flight mass spectrometry (MALDI-TOF MS) with the use of graphene as matrix. MALDI-TOF MS with conventional matrix
has limitations in analyzing low-polarity compounds owing to their difficulty in ionization. We demonstrate that compared
with conventional matrix, graphene displays higher desorption/ionization efficiencies for PAHs, and no fragment ions are observed.
The method also holds potential in quantitative analysis. In addition, the ionization signal increases with the increasing
number of benzene rings in the PAHs, suggesting that graphene binds to PAHs via π–π stacking interactions. Furthermore, graphene
as adsorbent for solid-phase extraction of coronene from river water sample displays good performance with a detection limit
of 10–7 M. This work provides a novel and convenient method for analyzing low-polarity environmental contaminants by MALDI-TOF MS. 相似文献
7.
Glutathione peroxidase (isolated from bovine erythrocytes) and its behaviour during alkylation and enzymatic digestion were
studied by various hyphenated techniques: gel electrophoresis–laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry
(MS), size-exclusion liquid chromatography–ICP MS, capillary high-performance liquid chromatography (capHPLC)–ICP MS, matrix-assisted
laser desorption/ionization (MALDI) time-of-flight (TOF) MS, electrospray MS, and nanoHPLC–electrospray ionization (ESI) MS/MS.
ESI TOF MS and MALDI TOF MS allowed the determination of the molecular mass but could not confirm the presence of selenium
in the protein. The purity of the protein with respect to selenium species could be evaluated by LA ICP MS and size-exclusion
chromatography (SEC)–ICP MS under denaturating and nondenaturating conditions, respectively. SEC–ICP MS and capHPLC–ICP MS
turned out to be valuable techniques to study the enzymolysis efficiency, miscleavage and artefact formation during derivatization
and tryptic digestion. For the first time the parallel ICP MS and ESI MS/MS data are reported for the selenocysteine-containing
peptide extracted from the gel; capHPLC–ICP MS allowed the sensitive detection of the selenopeptide regardless of the matrix
and nanoHPLC–electrospray made possible its identification.
Figure Eye catching image
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
A Fourier-transform ion cyclotron resonance (FT-ICR) top-down mass spectrometry strategy for determining the adenosine triphosphate
(ATP)-binding site on chicken adenylate kinase is described. Noncovalent protein-ligand complexes are readily detected by
electrospray ionization mass spectrometry (ESI-MS), but the ability to detect protein-ligand complexes depends on their stability
in the gas phase. Previously, we showed that collisionally activated dissociation (CAD) of protein-nucleotide triphosphate
complexes yield products from the dissociation of a covalent phosphate bond of the nucleotide with subsequent release of the
nucleotide monophosphate (Yin, S. et al., J. Am. Soc. Mass Spectrom.
2008, 19, 1199–1208). The intrinsic stability of electrostatic interactions in the gas phase allows the diphosphate group to remain
noncovalently bound to the protein. This feature is exploited to yield positional information on the site of ATP-binding on
adenylate kinase. CAD and electron capture dissociation (ECD) of the adenylate kinase-ATP complex generate product ions bearing
monoand diphosphate groups from regions previously suggested as the ATP-binding pocket by NMR and crystallographic techniques.
Top-down MS may be a viable tool to determine the ATP-binding sites on protein kinases and identify previously unknown protein
kinases in a functional proteomics study. 相似文献
9.
We present here a high-performance liquid chromatography−tandem mass spectrometry (LC-MS/MS) method for quantifying phytoestrogenic
isoflavones (daidzein, equol, genistein, and O-desmethylangolensin) and lignans (enterodiol and enterolactone) in urine without the use of extraction or the preconcentration
techniques inherent in existing methods. The development of this concept was made possible by use of atmospheric pressure
photoionization (APPI); an ionization technique that we found to improve analyte sensitivity relative to electrospray ionization
and atmospheric pressure chemical ionization for this particular group of compounds. The analytical performance of this method
was equal to or exceeded that of comparable methods. Between-run coefficients of variation (CVs) across three quality control
(QC) pool levels analyzed in duplicate over 20 days were 3.1–5.8% CV; within-run CVs were 2.3–6.0%. Accuracy, as determined
by average spike recovery in QC pools, was generally within ±10% of being quantitative (100%). Relative limits of detection
were 0.04–0.4 ng/mL urine, with absolute detection limits as low as 0.1 pg. This method was applied to the analysis of >2,500
urine specimens for the 2005–2006 Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey
(NHANES). The method was capable of quantifying these compounds in 95–100% of study samples. This work is the first ever report
of using APPI for the LC-MS/MS determination of these compounds in urine. It is also the first method of its kind to do so
without any need for analyte extraction or preconcentration prior to analysis. 相似文献
10.
Wang CZ Su Y Wang HY Guo YL 《Journal of the American Society for Mass Spectrometry》2011,22(10):1839-1850
When using tetrachloromethane as the reagent gas in gas chromatography-ion trap mass spectrometry equipped with hybrid ionization
source, the cation CCl3+ was generated in high abundance and further gas-phase experiments showed that such an electron-deficient reagent ion CCl3+ could undergo interesting ion–molecule reactions with various volatile organic compounds, which not only present some informative
gas-phase reactions, but also facilitate qualitative analysis of diverse volatile compounds by providing unique mass spectral
data that are characteristic of particular chemical structures. The ion–molecule reactions of the reagent ion CCl3+ with different types of compounds were studied, and results showed that such reactions could give rise to structurally diagnostic
ions, such as [M + CCl3 – HCl]+ for aromatic hydrocarbons, [M – OH]+ for saturated cyclic ether, ketone, and alcoholic compounds, [M – H]+ ion for monoterpenes, M·+ for sesquiterpenes, [M – CH3CO]+ for esters, as well as the further fragment ions. The mechanisms of ion–molecule reactions of aromatic hydrocarbons, aliphatic
ketones and alcoholic compounds with the reagent ion CCl3+ were investigated and proposed according to the information provided by MS/MS experiments and theoretical calculations. Then,
this method was applied to study volatile organic compounds in Dendranthema indicum var. aromaticum and 20 compounds, including monoterpenes and their oxygen-containing derivatives, aromatic hydrocarbon and sesquiterpenes
were identified using such ion–molecule reactions. This study offers a perspective and an alternative tool for the analysis
and identification of various volatile compounds. 相似文献
11.
Meier SM Tsybin YO Dyson PJ Keppler BK Hartinger CG 《Analytical and bioanalytical chemistry》2012,402(8):2655-2662
The interaction between oxaliplatin and the model protein ubiquitin (Ub) was investigated in a top–down approach by means
of high-resolution electrospray ionization mass spectrometry (ESI-MS) using diverse tandem mass spectrometric (MS/MS) techniques,
including collision-induced dissociation (CID), higher-energy C-trap dissociation (HCD), and electron transfer dissociation
(ETD). To the best of our knowledge, this is the first time that metallodrug–protein adducts were analyzed for the metal-binding
site by ETD-MS/MS, which outperformed both CID and HCD in terms of number of identified metallated peptide fragments in the
mass spectra and the localization of the binding sites. Only ETD allowed the simultaneous and exact determination of Met1
and His68 residues as binding partners for oxaliplatin. CID-MS/MS experiments were carried out on orbitrap and ion cyclotron
resonance (ICR)-FT mass spectrometers and both instruments yielded similar results with respect to number of metallated fragments
and the localization of the binding sites. A comparison of the protein secondary structure with the intensities of peptide
fragments generated by collisional activation of the [Ub + Pt-(chxn)] adduct [chxn = (1R,2R)-cyclohexanediamine] revealed a correlation with cleavages in solution phase random coil areas, indicating that the N-terminal β-hairpin and α-helix structures are retained in the gas phase. 相似文献
12.
13.
Sampson JS Hawkridge AM Muddiman DC 《Journal of the American Society for Mass Spectrometry》2006,17(12):1712-1716
We report the coupling of a hybrid ionization source, matrix-assisted laser desorption electrospray ionization (MALDESI), to a Fourier transform-ion cyclotron resonance mass spectrometer (FT-ICR MS). The details of the source design and initial data are presented. Analysis of peptides and proteins ranging from 1 to 8.6 kDa resulted in high resolving power single-acquisition FT-ICR mass spectra with average charge-states highly correlated to those obtained by nanoESI, thus, providing strong evidence that the ESI process dictates the observed charge-state distribution. Importantly, unlike the recently introduced electrospray assisted laser desorption ionization (ELDI) source reported by Shiea and coworkers [1, 2], the data we have obtained to date rely on the use of an organic acid matrix. The results presented herein provide insight into the charging mechanism of this emerging ionization approach, while also expanding the utility of FT-ICR MS for top-down protein and complex mixture analysis. 相似文献
14.
Introduction Mass spectrometry (MS) has been an important technique for studying size-dependent cluster properties with unparalleled sensitivity, specificity, and versatil-ity.1,2 Especially Fourier transform ion cyclotron reso-nance (FT-ICR) MS offers the benefits of ultra-high mass resolving power, superior mass accuracy, and the ability of affording useful structure information with tandem MS. The introduction of electrospray ionization (ESI) as a gentle mode of ion generation for MS… 相似文献
15.
Tandem mass spectrometry (MS/MS) of intact, noncovalently-bound protein-ligand complexes can yield structural information on the site of ligand binding. Fourier transform ion cyclotron resonance (FT-ICR) top-down MS of the 29 kDa carbonic anhydrase-zinc complex and adenylate kinase bound to adenosine triphosphate (ATP) with collisionally activated dissociation (CAD) and/or electron capture dissociation (ECD) generates product ions that retain the ligand and their identities are consistent with the solution phase structure. Increasing gas phase protein charging from electrospray ionization (ESI) by the addition of supercharging reagents, such as m-nitrobenzyl alcohol and sulfolane, to the protein analyte solution improves the capability of MS/MS to generate holo-product ions. Top-down proteomics for protein sequencing can be enhanced by increasing analyte charging. 相似文献
16.
Arráez-Román D Zurek G Bässmann C Almaraz-Abarca N Quirantes R Segura-Carretero A Fernández-Gutiérrez A 《Analytical and bioanalytical chemistry》2007,389(6):1909-1917
In this work, a new, easy and rapid method of analyzing phenolic compounds in pollen extract, based on capillary electrophoresis
coupled with electrospray ionization time-of-flight-mass spectrometry (CE–ESI–TOF–MS), has been developed. A systematic investigation
of separation parameters has been performed with respect to resolution, sensitivity, analysis time and peak shape. The electrophoretic
parameters and electrospray conditions must be optimized to obtain reproducible analyses. Using this method, several important
phenolic compounds such as acetin-glucoside, 7-O-methylherbacetin-3-sophoroside, galloyl-glucose, quercetin-3-sophoroside,
apigenin-6,8-di-C-glycoside, quercetin-3-rutinoside, genistein-7-O-β-D-glucoside, luteolin-7-O-glucoside, apigenin-7-O-glucoside and 2′,4′,6′-trihydroxy-3′-formyldihydrochalcone have been determined
directly from pollen extract. The efficiency, the rapidity, the small amounts of sample required, and the high resolution
of CE coupled with the sensitivity, the selectivity, the accurate masses and the true isotopic patterns obtained using TOF-MS
point to the potential of this approach for identifying the phenolic compounds present in pollen. 相似文献
17.
Miao Hu Chuang Guo Linzhou Zhang Suoqi Zhao Keng H. Chung Chunming Xu Quan Shi 《中国科学:化学(英文版)》2017,60(2):284-292
Delayed coking is an important petroleum resid conversion process. The processability of coking liquids is known to be dependent on the heteroatom compounds present in the coking liquids. Eight commercial delayed coking liquids were characterized by electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and gas chromatographic techniques. High relatively abundant heteroatom compounds in the coking liquids were 1–4 aromatic-ring pyridinic nitrogen compounds, carbazoles, benzocarbazoles, phenols, mercaptans, benzothiophenes, dibenzothiophenes, and naphthobenzothiophenes. Coking liquids derived from various feeds had similar compound class types, molecular weight distribution ranges, and double bond equivalents (DBE). However, the concentration of individual compounds and the distribution of DBE versus carbon number of heteroatom compounds varied. A comparison of heteroatom compounds in coker feeds and products revealed the various reaction mechanism of heteroatom compounds occurred during the coking process. The results suggested that molecular-level process models can be developed for optimization of unit operation to obtain desirable products that meet the environmental specifications and quality requirements. 相似文献
18.
Strife RJ Robosky LC Garrett G Ketcha MM Shaffer JD Zhang N 《Rapid communications in mass spectrometry : RCM》2000,14(4):250-260
The analysis of data within multi-generational, genealogical, electrospray ionization/MS(n) fragmentation maps is discussed in reference to the structure elucidation of morphinans, an important class of pharmacological compounds. Various general approaches to separate and understand observed processes are discussed. These include: (1) Simple synthetic schemes incorporating deuterium and (13)C into morphinans to study later-generation, O-methyl group migration; (2) labeling to understand 'intense' signals for even-electron to odd-electron ion 'switching' events; (3) gas phase 'synthesis' of proposed MS(3) ions via an independent route, using chemical ionization (CI) MS/MS of naphthalenes and analysis via a bench-top El/Cl ion trap; (4) a useful synthetic paradigm for generating proposed carbonium ion structures at MS(4) via electrospray ionization (ESI) of easily synthesized amines; (5) the analysis of an oxidation product and correlation of MS(n) data of a switched, odd-electron species with electron ionization and low-pressure, low-energy charge exchange data; and (6) a new way of summarizing MS(n) data. Copyright -Copyright 2000 John Wiley & Sons, Ltd. 相似文献
19.
Wang R Allmendinger P Zhu L Gröhn AJ Wegner K Frankevich V Zenobi R 《Journal of the American Society for Mass Spectrometry》2011,22(7):1234-1241
In this work, we investigated the role of the nebulizer gas flow in electrosonic spray ionization (ESSI), by systematically
studying the relation between the flow and the ion signals of proteins, such as cytochrome c and holomyoglobin using ESSI-mass spectrometry (MS). When a neutral solution was delivered with a small sample flow rate
(≤5 μL/min), no obvious transition from electrospray ionization (ESI) to ESSI was found as the gas velocity varies from subsonic
to supersonic speed. Droplets mostly experienced acceleration instead of breakup by the high-speed nebulizer gas. On the contrary,
using particular experimental conditions, such as an acidic solution or high sample flow rate (≥200 μL/min), more folded protein
ions appear to be kept in droplets of diminishing size due to breakup by the high-speed nebulizer gas in ESSI compared with
ESI. Theoretical analyses and numerical simulations were also performed to explain the observed phenomena. These systematic
studies clarify the ionization mechanism of ESSI and provide valuable insight for optimizing ESSI and other popular pneumatically
assisted electrospray ionization methods for future applications. 相似文献
20.
This study presents a high-performance liquid chromatography–electrospray ionization–mass spectrometric (LC–ESI–MS) method
for the simultaneous determination of tramadol and acetaminophen in human plasma using phenacetinum as the internal standard.
After alkalization with saturated sodium bicarbonate, both compounds were extracted from human plasma with ethyl acetate and
were separated by HPLC on a Hanbon LiChrospher CN column with a mobile phase of 10 mM ammonium acetate buffer containing 0.5%
formic acid–methanol (40:60, v/v) at a flow rate of 1 mL min−1. Analytes were determined using electrospray ionization in a single quadrupole mass spectrometer. LC–ESI–MS was performed
in the positive selected-ion monitoring (SIM) mode using target ions at [M+H]+
m/z 264.3 for tramadol, [M+H]+
m/z 152.2 for acetaminophen and [M+H]+
m/z 180.2 for phenacetinum. Calibration curves were linear over the range of 5–600 ng mL−1 for tramadol and 0.03–16 μg mL−1 for acetaminophen. The inter-run relative standard deviations were less than 14.4% for tramadol and 12.3% for acetaminophen.
The intra-run relative standard deviations were less than 9.3% for tramadol and 7.9% for acetaminophen. The mean plasma extraction
recovery for tramadol and acetaminophen were in the ranges of 82.7–85.9 and 83.6–85.3%. The method was applied to study the
pharmacokinetics of a new formulation of tramadol/acetaminophen tablet in healthy Chinese volunteers. 相似文献