Spectrometric Characterization of Purified C60 and C70

1990 ◽  
Vol 206 ◽  
Author(s):  
Keith R. Lykke ◽  
Michael J. Pellin ◽  
Peter Wurz ◽  
Dieter M. Gruen ◽  
Jerry E. Hunt ◽  
...  
Keyword(s):  
Electronic Absorption ◽  
Mass Spectra ◽  
Fluorescence Spectra ◽  
Multiphoton Ionization ◽  
Negative Ions ◽  
Picosecond Laser ◽  
Laser Desorption ◽  
Signal To Noise ◽  
Neutral Species

ABSTRACTC60 and C70 were synthesized and purified according to published procedures. Both nanosecond and picosecond laser desorption from coated substrates gave copious positive and negative ions. Mass spectra (TOF and FTMS) with excellent signal to noise, showing only the C60 and C70 mass peaks, have been observed. Well-resolved isotopic structure was seen in the FTMS spectra in agreement with the natural abundance of carbon. Laser desorption and multiphoton ionization/photodissociation of the neutral species, as well as electronic absorption, FTIR, and fluorescence spectra, have been obtained.

Structural Characterization of Fucose-Containing Oligosaccharides by High-Performance Liquid Chromatography and Matrix-Assisted Laser Desorption/ Ionization Time-of-Flight Mass Spectrometry

2001 ◽  
Vol 382 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Minoru Suzuki ◽  
Akemi Suzuki
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Structural Characterization ◽  
High Performance ◽  
Mass Spectra ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Column Temperature ◽  
Desorption Ionization

Abstract Eight pyridylamino (PA) derivatives of fucosecontaining oligosaccharides, which occur as free oligosaccharides in human milk and also are derived from glycosphingolipids, have been analyzed by highperformance liquid chromatography (HPLC) on normalphase and reversedphase columns, and by matrixassisted laser desorption/ionization timeofflight MALDITOF) mass spectrometry. Six out of eight PAoligosaccharides were clearly separated by both normal and reversedphase HPLC at a column temperature of 40 C, but two PAoligosaccharides, lactoNfucopentaose II [Gal?1-3(Fuc?1-4)GlcNAc?1- 3Gal?1-4GlcPA] and lactoNfucopentaose III Gal?1-4(Fuc?1-3)GlcNAc?1-3Gal?1-4GlcPA], were not separated. The two unresolved PAoligosaccharides were finally separated by reversedphase HPLC at a column temperature of 11 C. MALDITOF mass spectra of PAoligosaccharides demonstrated pseudomolecular ions as the predominant signals, therefore information about the molecular mass of each PAoligosaccharide was easily obtained. Postsource decay (PSD) MALDITOF mass spectra of PAoligosaccharides gave information about the carbohydrate sequences and carbohydrate species of each PAoligosaccharide by detecting the ions responsible for the cleavage of the glycosidic bonds. The detection limits of the PAoligosaccharides by HPLC, MALDITOF mass spectrometry, and PSD MALDITOF mass spectrometry were 20 fmol, 20 fmol, and 2 pmol, respectively. These results suggest that a system including HPLC and MALDITOF mass spectrometry or HPLC and PSD MALDITOF mass spectrometry is quite useful for the structural characterization of subpmol or pmol levels of fucosecontaining oligosaccharides, and that these methods could be used for the analysis of various types of oligosaccharides derived from glycoproteins and glycosphingolipids.

Resonant Two-Photon Ionization of CBZ-Derivatized Nonaromatic Peptides Using Pulsed Laser Desorption in Supersonic Beam Mass Spectrometry

1988 ◽  
Vol 42 (3) ◽  
pp. 411-417 ◽  
Author(s):  
Liang Li ◽  
David M. Lubman
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Pulsed Laser ◽  
Laser Desorption ◽  
Small Peptides ◽  
Neutral Species ◽  
Supersonic Expansion ◽  
Two Photon ◽  
Photon Ionization ◽  
Desorption Method

Resonant two-photon ionization (R2PI) of nonaromatic peptides is studied with the use of CBZ-derivatization as a means of providing an absorbing aromatic center in the near-UV region at 266 nm. The peptides are then vaporized with a pulsed laser-induced desorption method, with subsequent entrainment of the desorbed neutral species into a supersonic expansion. The CBZ-derivatized peptides are then ionized and mass analyzed in a time-of-flight mass spectrometer. The resulting R2PI/MPI-induced fragmentation-ionization patterns generally yield the molecular ion as well as fragments due to specific bond cleavages which are characteristic of the structure of the peptide. Thus, the resulting mass spectra can be used for identification and structural analysis of these small peptides. Most significantly, the laser-induced fragmentation can be used to distinguish between isomeric peptides containing Ile, Leu, or Nle.

Preparation and Characterization of a Novel Optical Material Based on Zinc-Tetraphenylporphyrin

2012 ◽  
Vol 476-478 ◽  
pp. 1254-1257
Author(s):  
Xiao Kang Li ◽  
Xiao Hui He ◽  
Yi Wang Chen ◽  
Xiao Lin Fan ◽  
Qing Dao Zeng
Keyword(s):  
Single Crystal ◽  
Absorption Spectra ◽  
Blue Light ◽  
Electronic Absorption ◽  
Fluorescence Spectra ◽  
Electronic Absorption Spectra ◽  
Supramolecular Complex ◽  
Optical Material ◽  
X Ray

Supramolecular complex，Zinc-tetraphenylporphyrin, 4,4’-azopyridine, Luminescence. Abstract. A new supramolecular complex(C44H28N4Zn)2•(C10H8N4)•(C7H8)(1) has been prepared by Zinc-tetraphenylporphyrin(ZnTPP) coordinated with 4,4’-azopyridine, which has been characterized by X-ray single-crystal diffraction.The electronic absorption spectra and fluorescence spectra reveal that the complex displays strong blue light and fluorescence, which is a good optical material.

Synthesis and Characterization of Potential and Degraded Impurities of Regadenoson

2020 ◽  
Vol 16 (8) ◽  
pp. 1130-1139
Author(s):  
Singaram Sathiyanarayanan ◽  
Chidambaram Subramanian Venkatesan ◽  
Senthamaraikannan Kabilan
Keyword(s):  
Mass Spectra ◽  
Degradation Products ◽  
Hplc Method ◽  
Forced Degradation ◽  
Spectroscopic Techniques ◽  
A2a Adenosine Receptor ◽  
Degradation Study ◽  
Related Substances ◽  
Adenosine Receptor Agonist

Background: Regadenoson is an A2A adenosine receptor agonist that is a coronary vasodilator and commonly used as a pharmacologic cardiac stressing agents. Methods: HPLC method was used for the analysis of related substances. The degraded impurities during the process were isolated and characterized by IR, Mass and NMR spectral analysis. Results: Forced degradation study of regadenoson under conditions of hydrolysis (neutral, acidic and alkaline) and oxidations suggested in the ICH Q1A(R2) was accomplished. The drug showed significant degradation under all the above conditions. On the whole, five novel degradation products were found under diverse conditions along with process related impurities which were not reported earlier. Conclusion: All the degradation products were well characterized by using advanced spectroscopic techniques like IR, 1H NMR, 13C NMR and Mass spectra. The identification of these impurities will be productive for the quality control during the production and stability behavior of the regadenoson drug substance.

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