Identification and Quantification of Surfactants in Oil Using the Novel Method for Chemical Fingerprinting Based on Electrospray Mass Spectrometry and Chemometrics

2006 ◽  
Vol 20 (3) ◽  
pp. 1161-1164 ◽  
Author(s):  
Ingvar Eide ◽  
Kolbjørn Zahlsen ◽  
Hege Kummernes ◽  
Gunhild Neverdal
2006 ◽  
Vol 84 (10) ◽  
pp. 1280-1289 ◽  
Author(s):  
Jeffery D Clarke ◽  
Keith Vaughan ◽  
Valerio Bertolasi

The reactions of a series of arene diazonium salts with 1,4,8,11-tetraazacyclotetradecane (cyclam) afford the novel compounds, the 1,4,8,11-tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes (1a–1f), which are the first examples of tetrakistriazenes to be reported. The tetrakistriazenes were characterized by IR spectroscopy, proton and carbon NMR, elemental analysis, high resolution electrospray mass spectrometry, and X-ray crystallography. The analogous reaction of a diazonium salt with 1,4,7-triazacyclononane or 1,5,9-triazacyclododecane yields the tristriazenes 2, 3a, and 3b. The structures of compounds 1c and 1e were solved by X-ray crystallography at low temperature (150 K). Both molecules display a conformation where the four phenyltriazenyl groups point alternately upwards and downwards with respect to the mean macrocyclic plane.Key words: triazene, tetrakistriazene, cyclam, tetraazacyclotetradecane, X-ray, NMR, cyclic polyamines.


1994 ◽  
Vol 12 (2) ◽  
pp. 69-83 ◽  
Author(s):  
Joseph Banoub ◽  
Emmanuel Gentil ◽  
Bougrine Tber ◽  
Nour-Eddine Fahmi ◽  
Gino Ronco ◽  
...  

Electrospray mass spectrometry has aided the structural characterization of 3'-azido-2',3'-dideoxythymidine (AZI) and the novel series of 3'-azido-2',3',4'trideoxy-4'-thio-S-(bromo, chi oro or fluoro )uridine nucleosides and their respective α.anomers. Low energy CAD MS/MS analysis of the protonated molecules [M+H]+confmned the predicted fragmentation route for AZT and a series of related 4'-thio-S-halogenouridines. This MSIMS study also provided characteristic fingerprint patterns which permitted differentiation of anomers within the series of 3'-azido-2' ,3' ,4' -trideoxy-4' -thio-S-halogenouridine nucleosides.


2013 ◽  
Vol 37 (4) ◽  
Author(s):  
August Goebel ◽  
Marcus Boehm ◽  
Hartmut Kirchherr ◽  
W. Nikolaus Kühn-Velten

AbstractDetection and quantification of synthetic cannabinoids (synonym: cannabimimetics) used as a substitute for natural cannabis has been a real toxicological and forensic issue since 2008. On the basis of a short overview of the pharmacological principle, chemical classification, and legal situation in Germany, the development of several analytical and screening approaches is presented. The paper further describes and validates a novel method for the simultaneous identification and quantification of JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, WIN48,098, WIN55,212-2, AM-694 and CP47,497 by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS) in human serum and hair using JWH-018-d


1994 ◽  
Vol 303 (3) ◽  
pp. 825-830 ◽  
Author(s):  
T H Farmer ◽  
J W J Page ◽  
D J Payne ◽  
D J C Knowles

The interactions of Staphylococcus aureus, Bacillus cereus I, TEM, Klebsiella pneumoniae K1 and Enterobacter cloacae P99 beta-lactamases with the novel penem inhibitor BRL 42715 were investigated kinetically and, in some cases, by electrospray mass spectrometry (e.s.m.s.). All the beta-lactamases were rapidly inactivated by BRL 42715, with second-order rate constants ranging from 0.17 to 6.4 microM-1.s-1. The initial stoichiometry of beta-lactamase inhibition was essentially 1:1, with the exception of the K1 enzyme. In this instance about 20 molecules of BRL 42715 were hydrolysed before the enzyme was completely inhibited. Inhibited beta-lactamases did not readily regain activity in the absence of BRL 42715, the half-lives for regeneration of free enzyme ranging from 5 min for the K1 beta-lactamase to over 2 days for the staphylococcal enzyme. Recovery of activity was incomplete for TEM-1, K1 and P99 beta-lactamases, suggesting partitioning of the inhibited enzymes to give a permanently (or at least very stable) inactivated species. Examination of the interactions of the penem with TEM, B. cereus I and P99 beta-lactamases by e.s.m.s. also showed rapid and stoichiometric binding of the inhibitor. In all cases a mass increase of 264 Da over the native enzyme was observed, corresponding to the molecular mass of BRL 42715, showing that no fragmentation of the penem occurred on reaction with the beta-lactamases.


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