A mass spectrometry study of n-octane: Electron impact ionization and ion-molecule reactions

2001 ◽  
Vol 114 (5) ◽  
pp. 2166-2172 ◽  
Author(s):  
C. Q. Jiao ◽  
C. A. DeJoseph ◽  
A. Garscadden
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Ion Molecule Reactions ◽  
Mass Spectrometry Study

Gas-Liquid Chromatographic/Mass Spectrometric Screening Method for T-2 Toxin in Milk

1979 ◽  
Vol 62 (6) ◽  
pp. 1274-1280
Author(s):  
George J Collins ◽  
Joseph D Rosen
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Chemical Ionization ◽  
Impact Ionization ◽  
Trimethylsilyl Ether ◽  
Screening Method ◽  
Internal Standard ◽  
Electron Impact Ionization ◽  
Gas Liquid Chromatography ◽  
Ionization Mass

Abstract A method for the analysis of T-2 toxin in milk is presented. Ethyl acetate extracts of milk samples which had been spiked with T-2 toxin were purified by thin layer chromatography and derivatized with N,O-bis(trimethylsilyl)acetamide to produce the T-2 toxin trimethylsilyl ether (T-2 toxin-TMS). N,O-bis(trimethylsilyl-d9)acetamide was used to make T-2 toxin d9-trimethylsilyl ether (T-2 toxin-d9TMS) which was added to the derivatized milk extract as an internal standard. Samples were analyzed by combined gas-liquid chromatography/mass spectrometry using either electron impact ionization or chemical ionization mass spectrometry. In electron impact ionization analyses, simultaneous monitoring of the T-2 toxin-TMS fragment ion at m/z 436 and the T-2 toxin-d9TMS fragment ion at m/z 445 gave a T-2 toxin-TMS detectability estimated at 6 μg/kg. In chemical ionization analyses, the T-2 toxin-TMS fragment ion at m/z 377 and the T-2 toxin-d9TMS fragment ion at m/z 386 were simultaneously monitored to give a T-2 toxin-TMS detectability estimated at 3 μg/kg. Average recovery was 85% at 200 μg/kg and 65% at 20 μg/kg.

Mass Spectrometry Study of Acylthioureas and Acylthiocarbamates

2002 ◽  
Vol 8 (5) ◽  
pp. 367-374 ◽  
Author(s):  
Roberto Martínez-Alvarez ◽  
Nazario Martín ◽  
Carlos Seoane ◽  
Ana María Plutin ◽  
Margarita Suárez ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electron Impact ◽  
Chemical Ionization ◽  
Impact Ionization ◽  
Fragmentation Process ◽  
Degradation Pathways ◽  
Ion Fragmentation ◽  
Mass Spectrometry Study ◽  
Sequential Product

A variety of acylthiocarbamates and acylthioureas have been investigated under electron impact ionization (EI), chemical ionization (CI) and electrospray ionization (ESI) conditions. Sequential product-ion fragmentation (MSn) was performed to elucidate the degradation pathways for these compounds. Comparisons are made between positive and negative even-electron ions from ESI and CI and the odd-electron ions obtained under EI conditions. The data collected in this paper provide information on the strong differences found in the fragmentation process of these compounds.

Detection by mass spectrometry of hydrocarbon biradicals, pyridine and aniline in a flame ionization detector

1982 ◽  
Vol 35 (8) ◽  
pp. 1743 ◽  
Author(s):  
M Head ◽  
T McAllister
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Aromatic Compounds ◽  
Mass Spectra ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Flame Ionization Detector ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Reaction Zones

The mass spectra of ions of > 75 in an f.i.d.-type flame with benzene additive have shown that hitherto undetected species of formulas CllH9+ and CI3H9+ are present, which may be attributed to protonation of the biradicals C11H8 and C13H8 by H3O+. The remainder of the hydrocarbon ions present are attributable to protonation of aromatic compounds (e.g. naphthalene and indene) which have been detected previously in premixed benzeneloxygen flames by electron impact ionization. Addition of NH3 to the benzene sample suppresses all the hydrocarbon peaks of m/z > 100 but generates new peaks of m/z 80 and 94, attributable to the protonation of pyridine and aniline. Aniline may be generated by addition of NH2 radicals to benzene in the pyrolysis and reaction zones of the flame.

Sign in / Sign up

Export Citation Format

Share Document