Mass spectrometry of heterocyclic compounds. V—Substituent effects on the fragmentation pathways of 3,5-diphenyl-1,2,4-oxadiazole derivatives

1974 ◽  
Vol 9 (6) ◽  
pp. 558-566 ◽  
Author(s):  
A. Selva ◽  
L. F. Zerilli ◽  
B. Cavalleri ◽  
G. G. Gallo
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic Compounds ◽  
Substituent Effects ◽  
Fragmentation Pathways ◽  
Oxadiazole Derivatives

scholarly journals Characterization and Study on Fragmentation Pathways of a Novel Nerve Agent, ‘Novichok (A234)’, in Aqueous Solution by Liquid Chromatography–Tandem Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1059
Author(s):  
Jin Young Lee ◽  
Kyoung Chan Lim ◽  
Hyun Suk Kim
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Liquid Chromatography ◽  
Degradation Products ◽  
Aqueous Sample ◽  
Tandem Mass ◽  
Aqueous Samples ◽  
Fragmentation Pathways ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

As a first step toward studying the properties of Novichok (ethyl (1-(diethylamino)ethylidene)phosphoramidofluoridate (A234)), we investigated its degradation products and fragmentation pathways in aqueous solution at different pH levels by liquid chromatography–tandem mass spectrometry. A234 was synthesized in our laboratory and characterized by nuclear magnetic resonance spectroscopy. Three sets of aqueous samples were prepared at different pH levels. A stock solution of A234 was prepared in acetonitrile at a concentration of 1 mg/mL and stored at −20 °C until use. Aqueous samples (0.1 mg/mL) were prepared by diluting the stock solution with deionized water. The acidic aqueous sample (pH = 3.5) and basic aqueous sample (pH = 9.4) were prepared using 0.01 M acetic acid and 0.01 M potassium carbonate, respectively. The analysis of the fragmentation patterns and degradation pathways of A234 showed that the same degradation products were formed at all pH levels. However, the hydrolysis rate of A234 was fastest under acidic conditions. In all three conditions, the fragmentation pattern and the major degradation product of A234 were determined. This information will be applicable to studies regarding the decontamination of Novichok and the trace analysis of its degradation products in various environmental matrices.

scholarly journals Mass Spectrometry of Heterocyclic Compounds: Benzo[b]pyrazolo[3,4-b]-1,6-naphthyridines

2016 ◽  
Vol 28 (11) ◽  
pp. 2385-2387
Author(s):  
Samia Khakwani ◽  
Samina Aslam ◽  
Mehrzadi Noureen Shahi ◽  
Alice M. Rolim Bernardino ◽  
Misbahul Ain Khan
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic Compounds

Differentiation of the Isomeric o-(m- and p-) Nitro-(Chloro- and Bromo-)Benzyl-2,4-(and 2,1-) Disubstituted 2-Thiocytosinium Halides by Electron Impact Ionisation and Fast Atom Bombardment Mass Spectrometry

2009 ◽  
Vol 15 (4) ◽  
pp. 497-506 ◽  
Author(s):  
Tomasz Pospieszny ◽  
Elżbieta Wyrzykiewicz
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Fast Atom Bombardment ◽  
Collision Induced Dissociation ◽  
Mass Measurements ◽  
Fragmentation Pathways ◽  
Mass Spectral ◽  
Fragment Ions ◽  
Accurate Mass Measurements ◽  
Impact Ionisation

Electron ionisation (EI) and fast atom bombardment (FAB) mass spectral fragmentations of nine 2,4-(and 2,1-) disubstituted o-( m- and p-)nitro-(chloro- and bromo-)-2-thiocytosinium halides are investigated. Fragmentation pathways, whose elucidation is assisted by accurate mass measurements and metastable transitions [EI-mass spectrometry (MS)], as well as FAB/collision-induced dissociation (CID) mass spectra measurements are discussed. The correlations between the abundances of the (C11H10N4SO2)+1–3; (C11H10N3SCl)+4–6 and (C11H10N3SBr)+7–9 ions and the selected fragment ions (EI-MS), as well as (C18H16N5SO4)+1–3; (C18H16N3SCl2)+4–6 and (C18H16N3SBr2) + 7–9 ions and the selected ions (C7H6NO2)+1–3; (C7H6Cl)+ 4–6; (C7H6Br)+ 7–9 (FAB-MS) are discussed. The data obtained can be used for distinguishing isomers.

Fragmentation pathways of heroin-related alkaloids revealed by ion trap and quadrupole time-of-flight tandem mass spectrometry

2008 ◽  
Vol 22 (18) ◽  
pp. 2851-2862 ◽  
Author(s):  
Zhengxiang Zhang ◽  
Bo Yan ◽  
Kelin Liu ◽  
Tao Bo ◽  
Yiping Liao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Ion Trap ◽  
Time Of Flight ◽  
Tandem Mass ◽  
Fragmentation Pathways
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