scholarly journals Positive Ion Chemistry of SiH4/GeF4 Gaseous Mixtures Studied by Ion Trap Mass Spectrometry and Ab Initio Calculations

2011 ◽  
Vol 17 (3) ◽  
pp. 197-206
Author(s):  
Lorenza Operti ◽  
Roberto Rabezzana ◽  
Francesca Turco ◽  
Stefano Borocci ◽  
Maria Giordani ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Ion Trap ◽  
Ion Trap Mass Spectrometry ◽  
Ion Chemistry ◽  
Gaseous Mixtures ◽  
Positive Ion

Positive Ion Chemistry of SiH4/NF3 Gaseous Mixtures Studied by Ion Trap Mass Spectrometry

2009 ◽  
Vol 15 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Paola Antoniotti ◽  
Lorenza Operti ◽  
Roberto Rabezzana ◽  
Francesca Turco ◽  
Stefano Borocci ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Charge Transfer ◽  
Rate Constants ◽  
Ion Trap ◽  
Ion Trap Mass Spectrometry ◽  
Ion Chemistry ◽  
Gaseous Mixtures ◽  
Secondary Ions ◽  
Primary Ions ◽  
Positive Ion

The positive ion chemistry occurring in silane/nitrogen trifluoride gaseous mixtures has been investigated by ion trap mass spectrometry. Reaction sequences and rate constants have been determined for the processes involving the primary ions SiH n+ ( n = 0–3) and NF x+ ( x = 1–3) and the secondary ions obtained from their reactions with SiH4 and NF3. The SiH n+ efficiently react with NF3 and undergo cascades of abstraction and scrambling reactions which form the fluorinated and perfluorinated cations SiHF m+ ( m = 1, 2), SiH2F+ and SiF x+ ( x = 1–3). Fluorinated Si2-clusters such as Si2H2F+, Si2H3F+ and Si2H5F+ were also observed. The reaction of both SiH3+ and SiH2F+ with NF3 produces the elusive fluoronitrenium ion NHF+. Any NF x+ reacts with SiH4 mainly by charge transfer. Additional ionic products are, however, observed which suggest intimate reaction complexes. Worth mentioning is the formation of SiNH2+ from the reaction of both NF+ and NHF+ with SiH4. The primary ions NF2+ and SiH3+ are also “sink” species in our observed chemistry.

Positive electrospray ionization ion trap mass spectrometry and ab initio computational studies of the multi-pathway fragmentation of oxoaporphine alkaloids

2017 ◽  
Vol 418 ◽  
pp. 30-36 ◽  
Author(s):  
Felipe M.A. da Silva ◽  
Giovana A. Bataglion ◽  
Richardson A. de Almeida ◽  
Gabriel Heerdt ◽  
Iran L. Sousa ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ab Initio ◽  
Electrospray Ionization ◽  
Ion Trap ◽  
Ion Trap Mass Spectrometry ◽  
Computational Studies

Fragmentation Pathway of Acevaltrate by Electro-Spray Ionization Ion-Trap Mass Spectrometry

2011 ◽  
Vol 361-363 ◽  
pp. 1745-1747
Author(s):  
Yong Gang Liu ◽  
Yong Liu ◽  
Qun Ma
Keyword(s):  
Mass Spectrometry ◽  
Ion Trap ◽  
Fragmentation Pathway ◽  
The Other ◽  
Collision Induced Dissociation ◽  
Ion Trap Mass Spectrometry ◽  
Electro Spray Ionization ◽  
Branched Chain ◽  
Positive Ion

The fragmentation pathway of acevaltrate was investigated by electro-spray ionization ion-trap mass spectrometry．Under the positive ion mode, pseudo-molecular [M+Na]+ could be easily obtained，and fragmentation pathway presented a certain regularity. One of the major fragmentations observed in the collision induced dissociation(CID) spectrum was loss of branched-chain, and the other was that three-membered oxygen-containing rings would break into aldehyde. These results might be used to forecast the structures of irodoids.

TRIGLYCERIDE COMPOSITION OF SIXTEEN STRAINS OF MARINE DIATOM

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Lily M.G. Panggabean ◽  
Abdullah Rasyid ◽  
Zarrah Duniani ◽  
Yana Meliana ◽  
Indah Kurniasih
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acid ◽  
Double Bond ◽  
Unsaturated Fatty Acid ◽  
Ion Trap ◽  
Carbon Chain ◽  
Highly Unsaturated Fatty Acid ◽  
Marine Diatom ◽  
Ion Trap Mass Spectrometry ◽  
Spectra Analysis

Trigliceride or triacylglicerol (TAG) composition in crude oil of sixteen strain of marine diatom has been detected by spectra analyses on an Electrospray - Ion Trap – Mass Spectrometry (ESI-IT-MS) HCT Bruker-Daltonic GmbH instrument with AgNO3 used as coordination ionization agent. Biomass samples of each microalga strain were taken from early and late stationary cultures in f/2 enriched seawater and algal oils were extracted according to Bligh and Dyer. Results from spectra analysis showed that P-Pt-P (C16:0-C16:1-C16:0) were distinguished in TAG from diatom strains Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.1, Thalasiossira sp.2, Thalasiossira sp.3, Navicula sp. 1, Navicula sp. 2, Navicula sp. 3, Navicula sp. 4, Nitzschia sp. 2 and Amphora sp. In contrast, TAGs in Melosira sp. included P-P-P (C16:0-C16:0-C16:0) and P-P-O (C16:0-C16:0-C18:1) were identified. TAGs from Chaetoceros sp. were the most varies among samples, i.e. P-Pt-P (C16:0-C16:1-C16:0), A-P-M (C20:4-C16:0-C14:0), P-Pt-Lt (C16:0-C16:1-C18:3), P-Pt-A (C16:0-C16:1-C20:4), D-P-P (C22:6-C16:0-C16:0), A-Ln-P (C20:4-C18:2-C16:0). Various TAGs were also detected in Nitzschia sp.2, i.e. P-Pt-M (C16:0-C16:1-C14:0), P-Pt-P (C16:0-C16:1-C16:0), P-Pt-S (C16:0-C16:1-C18:0), P-Pt-A (C16:0-C16:1-C20:4). TAGs composition in Skeletonema strains that similar to those in Nitzschia sp.1 has longer carbon, i.e. P-P-O (C16:0-C16:0-C18:1), P-O-O (C16:0-C18:1-C18:1) and O-O-O (C18:1-C18:1-C18:1). TAGs with longer carbon chain and more double bond including highly unsaturated fatty acid C20:4 were increased with culture age in diatoms Chaetoceros sp.1, Chaetoceros sp.2, Thalasiossira sp.2, Navicula sp.1 and Nitzschia sp. 2.Keywords: diatom, TAG, ESI-IT-MS, f/2, early and late stationary

Electron spray ion trap mass spectrometry of isoflavones and isoflavone aglycones of Semen Sojae Praeparatum

2013 ◽  
Vol 33 (10) ◽  
pp. 1108-1115
Author(s):  
Gao FANG ◽  
Peng ZHANG ◽  
Xiao-lan YE ◽  
Xia ZHU ◽  
Xin ZHAO ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Trap ◽  
Ion Trap Mass Spectrometry
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