Products from interaction of aromatic nitrocompounds with argon metastables inside a gas chromatograph

1981 ◽  
Vol 59 (10) ◽  
pp. 1439-1448 ◽  
Author(s):  
Walter A. Aue ◽  
Veluppillai Paramasigamani ◽  
Jae H. Kim
Keyword(s):  
Mass Spectrometry ◽  
Nitro Group ◽  
Gas Chromatograph ◽  
Chromatographic System ◽  
Penning Ionization ◽  
Aromatic Nitrocompounds ◽  
Discharge Chemistry

The neutral products resulting from the degradation of aromatic nitrocompounds, following interaction with argon metastables (presumably by Penning ionization), have been studied inside a gas chromatographic system. The simplest but typical example, nitrobenzene, yields benzene and phenol. Product ratios sometimes resemble results of mass spectrometry more than they do data obtained by pyrolysis. The ease of elimination of substituents from monohalogenated nitrobenzenes follows the order I > NO2 > Br > Cl. Ratios of the products resulting from loss of NO (rearrangement) versus loss of NO2 have been measured for a variety of compounds. The leaving NO2 group can be replaced by I if the system is doped with iodine vapour. Reduction of the nitro group and ring closures are observed with some of the more complex substrates, similar to results known from discharge chemistry.

Methods to Determine Phytopharmaceuticals in Tobacco and Tobacco Products. 4th Report: A Procedure to Determine Vamidothion and its Metabolites/Methoden zur Bestimmung von Phytopharmaka in Tabak und Tabakerzeugnissen: IV. Mitteilung: Ein Bestimmungsverfahren fuer Vamidothion und seine Metaboliten

1977 ◽  
Vol 9 (2) ◽  
Author(s):  
A.N. Sagredos ◽  
R. Moser
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Aluminium Oxide ◽  
Nuclear Magnetic Resonance Data ◽  
Gas Chromatograph ◽  
Tobacco Products ◽  
Magnetic Resonance Data ◽  
Resonance Data

AbstractBased on previous work (7) a method to simultaneously determine vamidothion [I], vamidothion-sulfoxide [II] and vamidothion sulfone [III] in tobacco has been developed. The compounds are extracted with water/acetone/acetic acid from the tobacco, cleansed over an aluminium oxide column and then determined on the gas chromatograph with the specific sulphur detector. Rates of recovery are 70 % - 92 %, the determination level is 0.1 ppm. Mass spectrometry and nuclear magnetic resonance data of vamidothion [I], vamidothion-sulfoxide [ II ] and vamidothion-sulfone [III] are given.

scholarly journals Potential insecticidal activity of four essential oils against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7767-7783
Author(s):  
Mohamed E. Tawfeek ◽  
Hayssam M. Ali ◽  
Mohammad Akrami ◽  
Mohamed Z. M. Salem
Keyword(s):  
Mass Spectrometry ◽  
Alkaline Phosphatase ◽  
Sitophilus Oryzae ◽  
Imperata Cylindrica ◽  
Rice Weevil ◽  
Gas Chromatograph ◽  
Cymbopogon Citratus ◽  
Phytochemical Composition ◽  
Germacrene D ◽  
Gas Chromatograph Mass Spectrometry

Oils extracted from Cymbopogon citratus, Lantana camara, Artemisia camphorata, and Imperata cylindrica plants were used as potential insecticides against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae). The phytochemical composition of the isolated oils was identified by gas chromatograph-mass spectrometry (GC-MS). Oil contact toxicities were evaluated against the adults of S. oryzae. The activities of acetylcholinesterase (AChE), alkaline phosphatase (ALP), and transaminases enzymes (AST) were measured. L. camara oil (LC50 = 9.81 mg/cm2) demonstrated the highest effect, followed by C. citratus oil (LC50 = 10.89 mg/cm2), A. camphorata EO (LC50 = 16.12 mg/cm2), and I. cylindrica oil (LC50= 36.85 mg/cm2) against the adults of S. oryzae. The inhibition percentages of AChE were 38.8, 41.7, 35.0, and 27.2%; ALP were 42.4, 49.3, 28.1, and 18.7%; AST were 33.9, 38.7, 20.8, and 11.8%; and ALT were 22.7, 30.5, 14.6, and 9.6% after treated S. oryzae with oils from C. citratus, L. camara, A. camphorata and I. cylindrica, respectively. The highest abundant compounds in C. citratus were geranial (25.95%), nerylacetal (8.85%), and neral (8.45%), in L. camara were caryophyllene (12.2%), and 3-elemene (8.89%), in A. camphorata were germacrene D-4-ol (20.83%), and borneol (19.47%), and in I. cylindrica were 5-phenylundecane (10.68%), and 6-phenyldodecane (8.70%).

Electrospray Tandem Mass Spectrometry of β-Nitroalkenyl Meso-Tetraphenylporphyrins

2008 ◽  
Vol 14 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Eduarda M.P. Silva ◽  
Pedro Domingues ◽  
João P.C. Tomé ◽  
M. Amparo F. Faustino ◽  
M. Graça P.M.S. Neves ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Nitro Group ◽  
Relative Abundance ◽  
Bromine Atom ◽  
Tandem Mass ◽  
Fragmentation Pattern ◽  
Free Base ◽  
Electrospray Tandem Mass Spectrometry ◽  
Esi Ms

β-Nitroalkenyl meso-tetraphenylporphyrins [β-TPPCHC(NO2)R)], as free-bases and Zn(II) complexes, were studied by electrospray mass spectrometry (ESI-MS). Under this ionisation condition the [M + H]+ ions are formed. The fragmentation pattern of the resulting [M + H]+ ions were studied by electrospray tandem mass spectrometry (ESI-MS/MS). The ESI-MS/MS of β-nitroalkenylporphyrins, either as free-bases or as Zn(II) complexes, show several interesting features, distinct from the typical behaviour of nitro compounds. For the studied compounds, common main fragmentation patterns are observed, namely characteristic losses of NO2•, HNO2, 2OH•, RNO2, RCNO, RCNO2, RCH2NO2, C6H5• plus NO2• and the formation of the protonated macrocycle, [TPP + H]+ or [ZnTPP + H]+. However, depending on the presence or absence of the metal and the nature of the R substituent, important differences are observed on the relative abundances of the ions formed by the same fragmentation pathway. The presence of bromine in the alkenyl group leads to a peculiar behaviour, since the main fragmentation pattern corresponds to the combined elimination of the bromine atom with the typical nitro group fragments. When R = Br, the loss of the nitro group occurs in low relative abundance (11-16%). However, when R = CH3, the relative abundance of the ion due to the loss of HNO2 changes drastically from 100%, observed for the free-base porphyrin, to 29% in the case of the Zn(II) complex. These variations of the relative abundance of the fragment corresponding to the loss of the nitro moiety (typically considered as a diagnostic fragment) can induce to an erroneous interpretation of their MS/MS spectra. Some fragmentations are observed only for the free-base porphyrins, namely the loss of •CH(NO2)R and HNO2 plus C2H2, while the loss of OH•, H2O, OH• plus H2O and RCCH plus H2O is observed only for the complexes. Unusual and unexpected fragmentations are also observed, namely the losses of RCNO, RCNO2 and HNO2 plus C2H2. This work demonstrates that valuable structural information about the β-nitroalkenyl substituents linked to meso-tetraarylporphyrins can be achieved using MS/MS. These results can also be useful for the interpretation of the mass spectra of other nitroalkenyl substituted compounds.

Separation and Characterization of Amine Drugs and Their Enantiomers by Capillary Column Gas Chromatography-Mass Spectrometry

1983 ◽  
Vol 66 (6) ◽  
pp. 1443-1446
Author(s):  
Ray H Liu ◽  
Warren W Ku ◽  
Mary P Fitzgerald
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Mass Spectrometer ◽  
Capillary Column ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Chromatograph ◽  
Capillary Column Gas Chromatography ◽  
Spectrometer Data ◽  
Amine Drug

Abstract A gas chromatograph-mass spectrometer-data system equipped with a capillary column is used to analyze commonly abused amine drug mixtures. Enantiomeric amines are analyzed as N-trifluoroacetyl- I-prolyl chloride derivatives. The 10 compounds included in this study are amphetamine, methamphetamine, norephedrine, ephedrine, 3,-4-methylenedioxyamphetamine, N,N-dimethyltryptamine, N,N-diethyltryptamine, N,N-dimethyl-5-methoxytryptamine, mescaline, and caffeine. All compounds, including possible enantiomers, are resolved and identified by the described method.

Use of Dansyl Derivatives and Mass Spectrometry for Identification of Biogenic Amines

1968 ◽  
Vol 14 (4) ◽  
pp. 302-309 ◽  
Author(s):  
C R Creveling ◽  
K Kondo ◽  
J W Daly
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Biogenic Amines ◽  
Primary Amines ◽  
Mass Determination ◽  
Chromatographic System ◽  
Mammalian Heart ◽  
Heart Mass ◽  
Dansyl Derivatives ◽  
Derivatives Of

Abstract A useful technic for the isolation, separation, and identification of biogenic amines as fluores ent dansyl derivatives is described. A thin-layer chromatographic system is presented for the separation of the dansyl derivatives of phenethylamines from their corresponding β-hydroxyl derivatives, of primary amines from their corresponding N-alkylated derivatives, and of the components present in an extract of mammalian heart. Mass spectrums of dansyl derivatives of various amines and amino acids are presented to illustrate parent ion mass determination. This technic was applied to the identification of various amines present in mammalian heart. Identification was based on cochromatography and identity of parent ion mass with authentic compounds. Piperidine, dimethylamine, phenethylamine, methylamine, phenethanolamine, putrescine, spermidine, spermine, and tyramine were identified.

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