An atmospheric pressure chemical ionization study of the positive and negative ion chemistry of the hydrofluorocarbons 1,1-difluoroethane(HFC-152a) and 1,1,1,2-tetrafluoroethane(HFC-134a) and of perfluoro-n-hexane(FC-72) in air plasma at atmospheric pressure

2004 ◽  
Vol 39 (7) ◽  
pp. 791-801 ◽  
Author(s):  
Ester Marotta ◽  
Cristina Paradisi ◽  
Gianfranco Scorrano
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Atmospheric Pressure Chemical Ionization ◽  
Negative Ion ◽  
Air Plasma ◽  
Ion Chemistry ◽  
Hfc 134A ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical ◽  
Hfc 152A

Differentiation of (Mixed) Halogenated Dibenzo-p-Dioxins by Negative Ion Atmospheric Pressure Chemical Ionization

2016 ◽  
Vol 88 (10) ◽  
pp. 5205-5211 ◽  
Author(s):  
Sujan Fernando ◽  
M. Kirk Green ◽  
Kari Organtini ◽  
Frank Dorman ◽  
Rhys Jones ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Atmospheric Pressure Chemical Ionization ◽  
Negative Ion ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical

scholarly journals Determination of Nicarbazin in Eggs by Liquid Chromatography–Atmospheric Pressure Chemical Ionization Mass Spectrometry

1997 ◽  
Vol 80 (6) ◽  
pp. 1177-1182 ◽  
Author(s):  
W John Blanchflower ◽  
Peter J Hughes ◽  
D Glenn Kennedy
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Atmospheric Pressure Chemical Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Limit Of Quantitation ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical

Abstract A method was developed to determine in eggs 2 components [4,6-dimethyl-2-hydroxypyrimidine and 1,3-bis(4-nitrophenyl)urea] of the anticoccidial drug nicarbazin, used to treat poultry. Samples were extracted with acetonitrile, and the extracts were washed with hexane and evaporated to dryness before analysis by liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization. By switching from positive to negative ion monitoring and using gradient elution, both components were measured within one run. The limit of quantitation of the assay was 10 ng/g for each component. The results of a preliminary feeding trial in which chickens were fed contamination levels of the drug are also reported.

Analysis of minor constituents in fullerene soots by LC–MS using a heated pneumatic nebulizer interface with atmospheric pressure chemical ionization

1992 ◽  
Vol 70 (10) ◽  
pp. 2558-2568 ◽  
Author(s):  
J. F. Anacleto ◽  
R. K. Boyd ◽  
S. Pleasance ◽  
M. A. Quilliam ◽  
J. B. Howard ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Laminar Flame ◽  
Atmospheric Pressure Chemical Ionization ◽  
Inert Atmosphere ◽  
Negative Ion ◽  
Principal Minor ◽  
Minor Constituents ◽  
Pressure Chemical Ionization ◽  
Pressure Chemical

The minor constituents of toluene extracts of three fullerene-rich materials have been characterized by on-line LC–MS techniques, incorporating both positive and negative ion mass spectra obtained by atmospheric pressure chemical ionization. Two of the materials were soots, produced by resistive heating of graphite in an inert atmosphere, from different commercial suppliers. The third material was obtained as a condensate from a controlled laminar flame, and was shown previously (Anacleto etal:, Rapid Commun. Mass Spectrom. 6, 214 (1992)) to contain significant quantities of compounds that behaved under the present LC–MS conditions as isomers of the C60 and C70 fullerenes, and which reverted to the latter upon heating. This finding was confirmed here, and extended to the higher clusters C76, C84, C90, and C94. One of the graphite-derived soots contained monoxides of the carbon clusters as the principal minor components, while the other soot contained hydrogenated species including C60H2, C60H4, C70H2, and (C60•CH4). The flame-generated material contained all of these minor constituents, together with complexes of C60 with larger aliphatic molecules as well as large quantities of polycyclic aromatic hydrocarbons and related species. Photo-oxidation of a purified C60 preparation, from the graphitic soot containing mostly monoxide impurities, was shown to lead to increased levels of the mono-, di-, and tri-oxides of C60.

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