scholarly journals Characterization and Identification of Prenylated Flavonoids from Artocarpus heterophyllus Lam. Roots by Quadrupole Time-Of-Flight and Linear Trap Quadrupole Orbitrap Mass Spectrometry

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4591 ◽  
Author(s):  
Jin-Bao Ye ◽  
Gang Ren ◽  
Wen-Yan Li ◽  
Guo-Yue Zhong ◽  
Min Zhang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Structural Information ◽  
Structural Characteristics ◽  
Time Of Flight ◽  
Artocarpus Heterophyllus ◽  
Prenylated Flavonoids ◽  
Linear Trap ◽  
Orbitrap Mass Spectrometry ◽  
Group A ◽  
Successive Loss

In this study, a combination of quadrupole time-of-flight mass spectrometry (Q-TOF-MS) and linear trap quadrupole orbitrap mass spectrometry (LTQ-Orbitrap-MS) was performed to investigate the fragmentation behaviors of prenylated flavonoids (PFs) from Artocarpus plants. Fifteen PFs were selected as the model molecules and divided into five types (groups A–E) according to their structural characteristics in terms of the position and existing form of prenyl substitution in the flavone skeleton. The LTQ-Orbitrap-MSn spectra of the [M − H]− ions for these compounds provided a wealth of structural information on the five different types of compounds. The main fragmentation pathways of group A were the ortho effect and retro Diels–Alder (RDA), and common losses of C4H10, CO, and CO2. The compounds in group B easily lose C6H12, forming a stable structure of a 1,4-dienyl group, unlike those in group A. The fragmentation pathway for group C is characterized by obvious 1,4A−, 1,4B− cracking of the C ring. The diagnostic fragmentation for group D is obvious RDA cracking of the C ring and the successive loss of CH3 and H2O in the LTQ-Orbitrap-MSn spectra. Fragmentation with successive loss of CO or CO2, ·CH3, and CH4 in the LTQ-Orbitrap-MSn spectra formed the characteristics of group E. The summarized fragmentation rules were successfully exploited to identify PFs from Artocarpus heterophyllus, a well-known Artocarpus plant, which led to the identification of a total of 47 PFs in this plant.

Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

1990 ◽  
Vol 48 (2) ◽  
pp. 308-309
Author(s):  
Bruno Schueler ◽  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Time Of Flight ◽  
Biological Tissues ◽  
Polymer Surfaces ◽  
Tof Sims ◽  
Secondary Ions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

scholarly journals Amorphous Ge-Bi-Se Thin Films: A Mass Spectrometric Study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ravi Mawale ◽  
Govinda Mandal ◽  
Marek Bouška ◽  
Jan Gutwirth ◽  
Pankaj Lochan Bora ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Thin Films ◽  
Laser Ablation ◽  
Density Functional ◽  
Structural Information ◽  
Time Of Flight ◽  
Mass Spectrometry Analysis ◽  
Individual Species ◽  
Ablation Time ◽  
Flight Mass Spectrometry

AbstractThe Ge-Bi-Se thin films of varied compositions (Ge content 0–32.1 at. %, Bi content 0–45.7 at. %, Se content 54.3–67.9 at. %) have been prepared by rf magnetron (co)-sputtering technique. The present study was undertaken in order to investigate the clusters generated during the interaction of laser pulses with Ge-Bi-Se thin films using laser ablation time-of-flight mass spectrometry. The stoichiometry of the clusters was determined in order to understand the individual species present in the plasma plume. Laser ablation of Ge-Bi-Se thin films accompanied by ionization produces about 20 positively and/or negatively charged unary, binary and ternary (Gex+, Biy+, Sez+/−, GexSez+/−, BiySez+/− and GexBiySez−) clusters. Furthermore, we performed the laser ablation experiments of Ge:Bi:Se elemental mixtures and the results were compared with laser ablation time-of-flight mass spectrometry analysis of thin films. Moreover, to understand the geometry of the generated clusters, we calculated structures of some selected binary and ternary clusters using density functional theory. The generated clusters and their calculated possible geometries can give important structural information, as well as help to understand the processes present in the plasma processes exploited for thin films deposition.

scholarly journals Screening of Phosphodiesterase-5 Inhibitors and Their Analogs in Dietary Supplements by Liquid Chromatography–Hybrid Ion Trap–Time of Flight Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2734
Author(s):  
Unyong Kim ◽  
Hyun-Deok Cho ◽  
Myung Hee Kang ◽  
Joon Hyuk Suh ◽  
Han Young Eom ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Dietary Supplements ◽  
Ion Trap ◽  
Structural Information ◽  
Screening Method ◽  
Time Of Flight ◽  
Ion Source ◽  
Phosphodiesterase 5 Inhibitors ◽  
Flight Mass Spectrometry ◽  
Phosphodiesterase 5

An accurate and reliable method based on ion trap–time of flight mass spectrometry (IT–TOF MS) was developed for screening phosphodiesterase-5 inhibitors, including sildenafil, vardenafil, and tadalafil, and their analogs in dietary supplements. Various parameters affecting liquid chromatographic separation and IT–TOF detection were investigated, and the optimal conditions were determined. The separation was achieved on a reversed-phase column under gradient elution using acetonitrile and water containing 0.2% acetic acid at a flow rate of 0.2 mL/min. The chromatographic eluents were directly ionized in the IT–TOF system equipped with an electrospray ion source operating in the positive ion mode. The proposed screening method was validated by assessing its linearity, precision, and accuracy. Sequential tandem MS was conducted to obtain structural information of the references, and the fragmentation mechanism of each reference was proposed for providing spectral insight for newly synthesized analogs. Structural information, including accurate masses of both parent and fragment ions, was incorporated into the MSn spectral library. The developed method was successfully applied for screening adulterated dietary supplement samples.

Combination of Time-of-Flight Mass Analysers with Magnetic-Sector Instruments: In-Line and Perpendicular Arrangements. Applications to Poly(Ethylene Glycol) with Long-Chain end Groups

2000 ◽  
Vol 6 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Andrew R. Botrill ◽  
Anastassios E. Giannakopulos ◽  
Allen Millichope ◽  
Ken S. Lee ◽  
Peter J. Derrick
Keyword(s):  
Mass Spectrometry ◽  
Ethylene Glycol ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Orthogonal Experiment ◽  
Time Of Flight ◽  
High Energy ◽  
Poly Ethylene Glycol ◽  
End Groups ◽  
Poly Ethylene

High-energy collision-induced dissociation has been shown to provide extensive and detailed structural information on poly(ethylene glycol) with palmitoyl end-groups. Fragmentation within the end-groups provides direct information on their structures. Both in-line time-of-flight (TOF) and orthogonal TOF have been used for the measurement of fragment ions. Use of TOF as the second stage of mass spectrometry has facilitated exploitation of the pulsed method of ionisation matrix-assisted laser desorption/ionisation (MALDI). The orthogonal TOF instrument is used with a liquid secondary-ion mass spectrometry source. The laboratory-frame collision energies were different for in-line and orthogonal TOF, being 8–12 keV in the former and 800 eV in the latter. The tandem mass spectra were similar for the in-line experiment with either He or Xe collision gas and the orthogonal experiment with Xe. Mechanisms proposed for the fragmentations involve homolytic cleavage (C–H and backbone bonds) and invoke non-ergodicity.

Identification in Rat Plasma and Urine by Linear Trap Quadrupole–Orbitrap Mass Spectrometry of the Metabolites of Maslinic Acid, a Triterpene from Olives

2015 ◽  
Vol 63 (4) ◽  
pp. 1126-1132 ◽  
Author(s):  
Marta Sánchez-González ◽  
Glòria Lozano-Mena ◽  
Andrés Parra ◽  
M. Emília Juan ◽  
Joana M. Planas
Keyword(s):  
Mass Spectrometry ◽  
Rat Plasma ◽  
Maslinic Acid ◽  
Linear Trap ◽  
Orbitrap Mass Spectrometry
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