Negative ion chemical ionization mass spectral NICIMS) studies. reactions of metal Schiff base complexes with methane: gas mixtures

1979 ◽  
Vol 32 ◽  
pp. 11-17 ◽  
Author(s):  
Erwin Baumgartner ◽  
John G. Dillard
Keyword(s):  
Schiff Base ◽  
Chemical Ionization ◽  
Gas Mixtures ◽  
Schiff Base Complexes ◽  
Negative Ion ◽  
Ionization Mass ◽  
Mass Spectral ◽  
Methane Gas ◽  
Negative Ion Chemical Ionization

scholarly journals Discrimination of structural isomers of amphetamine using carbon dioxide negative-ion chemical ionization mass spectrometry

1997 ◽  
Vol 13 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Kevin B. Thurbide ◽  
C. M. Elson ◽  
P. G. Sim
Keyword(s):  
Carbon Dioxide ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Structural Isomers ◽  
Mass Spectral ◽  
Negative Ion Chemical Ionization ◽  
Spectral Behaviour ◽  
Carbon Dioxide Plasma

The negative‒ion chemical ionization mass spectra of a group of structural isomers of amphetamine have been studied using carbon dioxide as the reagent gas. Characteristic and reproducible differences are observed for each member of the set implying that this technique offers a means of distinguishing among groups of amphetamine isomers. Characteristic adducts to the molecular ion are observed in the form (M–[H]+[O]) and (M–[H]+[CO2]). Descriptions of some fragments are given based on the mass spectral behaviour of a set of analogue compounds and the results of oxygen-18 labelled carbon dioxide reagent gas experiments. Contents of the carbon dioxide plasma and their impact on various analytes is also discussed.

Mass Spectral Investigations on Trichothecene Mycotoxins. II. Detection and Quantitation of Macrocyclic Trichothecenes by Gas Chromatography/Negative Ion Chemical Ionization Mass Spectrometry

1987 ◽  
Vol 70 (1) ◽  
pp. 132-140
Author(s):  
Thaiya Krishnamurthy ◽  
Emory W Sarver ◽  
Sharon L Greene ◽  
Bruce B Jarvis
Keyword(s):  
Chemical Ionization ◽  
Accurate Determination ◽  
Negative Ion ◽  
Ionization Mass ◽  
Good Precision ◽  
Mass Spectral ◽  
Macrocyclic Trichothecenes ◽  
Negative Ion Chemical Ionization ◽  
Fermentation Broths

Abstract A general, sensitive gas chromatographic/negative ion chemical ionization mass spectrometric (GC/NICIMS) method of analysis was developed for the detection and quantitation of several polar, thermally labile, toxic macrocyclic trichothecenes. The procedure involves the conversion of the molecules to their corresponding alcohols (verrucarols) by alkaline hydrolysis, followed by derivatization of the hydrolysate with heptafluorobutyrylimidazole and analysis by GC/MS technique under negative ion chemical ionization conditions. Nanogram (250 ng) quantities of several macrocyclic trichothecenes with different verrucarol and ester moieties were analyzed successfully with good precision by this procedure. The method was applicable for the accurate determination of at least low ppb levels of these macrocyclic trichothecenes in environmental samples, such as fungal products, fermentation broths, and plant samples. This is the first reported, well developed, sensitive, and applicable method for the detection and quantitation of these compounds in naturally occurring samples.

The monomeric metaphosphate anion in negative-ion chemical-ionization mass spectra of phosphotriesters

1984 ◽  
Vol 106 (23) ◽  
pp. 6877-6883 ◽  
Author(s):  
Seymour Meyerson ◽  
Donald J. Harvan ◽  
J. Ronald Hass ◽  
Fausto Ramirez ◽  
James F. Marecek
Keyword(s):  
Mass Spectra ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Negative Ion Chemical Ionization
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