Standardizing the Novel Method for Chemical Fingerprinting of Oil and Petroleum Products Based on Positive Electrospray Mass Spectrometry and Chemometrics

2006 ◽  
Vol 20 (1) ◽  
pp. 265-270 ◽  
Author(s):  
Kolbjørn Zahlsen ◽  
Ingvar Eide
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Mass Spectrometry ◽  
Petroleum Products ◽  
The Novel ◽  
Chemical Fingerprinting ◽  
Novel Method

1,4,8,11-Tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes — Synthesis, characterization, and X-ray crystallography of the first tetrakistriazenes to be reported

2006 ◽  
Vol 84 (10) ◽  
pp. 1280-1289 ◽  
Author(s):  
Jeffery D Clarke ◽  
Keith Vaughan ◽  
Valerio Bertolasi
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Electrospray Mass Spectrometry ◽  
Diazonium Salt ◽  
Diazonium Salts ◽  
The Novel ◽  
Analogous Reaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Mean

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.

scholarly journals Electrospray Tandem Mass Spectrometry of 3'-azido-2',3'dideoxythymidine and of a Novel Series of 3'-azido-2',3',4'-trideoxy-4'thio-5-halogenouridines and their Respective α-Anomers

1994 ◽  
Vol 12 (2) ◽  
pp. 69-83 ◽  
Author(s):  
Joseph Banoub ◽  
Emmanuel Gentil ◽  
Bougrine Tber ◽  
Nour-Eddine Fahmi ◽  
Gino Ronco ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Structural Characterization ◽  
Electrospray Mass Spectrometry ◽  
Low Energy ◽  
Tandem Mass ◽  
The Novel ◽  
Electrospray Tandem Mass Spectrometry ◽  
Protonated Molecules

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.

scholarly journals Kinetic and physical studies of β-lactamase inhibition by a novel penem, BRL 42715

1994 ◽  
Vol 303 (3) ◽  
pp. 825-830 ◽  
Author(s):  
T H Farmer ◽  
J W J Page ◽  
D J Payne ◽  
D J C Knowles
Keyword(s):  
Mass Spectrometry ◽  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Electrospray Mass Spectrometry ◽  
Enterobacter Cloacae ◽  
Beta Lactamase ◽  
The Novel ◽  
Beta Lactamases ◽  
Enzyme Recovery ◽  
Mass Increase

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.

scholarly journals SYNTHESIS OF 2,2’ – DI-1,3-DIAZOPERENES

2019 ◽  
Author(s):  
М.Х. Магомадова ◽  
А.В. Аксенов ◽  
М.Х. Магомадова ◽  
Р.А. Турлуев ◽  
Э.У. Идрисова
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
The Novel ◽  
Two Dimensional ◽  
High Resolution Mass ◽  
Oxidative Aromatization ◽  
Novel Method ◽  
Peri Annelation ◽  
Resolution Mass

Разработан новый метод получения 1,3диазапиренов посредством пери-аннелирования пери мидинов 1,3дикарбонильными соединениями. Показано, что такой метод обладает рядом пре имуществ по сравнению с описанным ранее методом Пожарского-Боровлева, использующим халконы в качестве электрофильных компонентов и требующим окислительной ароматизации частично гидрированных промежуточных продуктов. Кроме того, показано, что новый метод от лично применим для эффективного двукратного пери-аннелирования бипeримидинов 1,3ди карбонильными соединениями с целью получения 2,2 би-1,3диазапиренов. Строение 2,2 ди-1,3диазапиренов подтверждено с помощью масс-спектрометрии высокого разрешения, 1Н и 13С ЯМР спектроскопии. В том числе, для этого использовались и двумерные методы HSQCE1H-13C и HMBC1H-13C. Элементный состав соединений определяли при помощи масс-спектрометрии вы сокого разрешения. A novel method of producing 1,3diazapirenes by peri-annelating perimidines with 1,3dicarbonyl compounds has been developed. This method is shown to have a number of advantages over the Pozharsky-Borovlev method described above, which uses halcones as electrophilic components and requires oxidative aromatization of partially hydrogenated intermediates. Furthermore, the novel method has been shown to be excellent for the effective double peri-annelation of the 1, 3dicarbonyl compounds to produce 2, 2 -bi-1,3diazapirenes. The structure of 2,2 -di-1,3diazapirenes was confirmed by high resolution mass spectrometry, 1Н and 13С NMR spectroscopy. This included two-dimensional methods of HSQCE1H-13C and HMBC1H-13C. The elemental composition of the compounds was determined by high resolution mass spectrometry.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

Analysis of Trace Level Perchlorate in Drinking Water and Ground Water by Electrospray Mass Spectrometry

1998 ◽  
Author(s):  
Rebecca A. Clewell ◽  
Wayne T. Brashear ◽  
David T. Tsui ◽  
Sanwat Chaudhuri ◽  
Rachel S. Cassady
Keyword(s):  
Mass Spectrometry ◽  
Drinking Water ◽  
Ground Water ◽  
Electrospray Mass Spectrometry ◽  
Trace Level
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