Imaging polymer supported organic molecules by mass spectrometry Application in combinatorial chemistry

2003 ◽  
Vol 804 ◽  
Author(s):  
C. Enjalbal ◽  
D. Maux ◽  
R. Combarieu ◽  
J. Martinez ◽  
J-L. Aubagnac
Keyword(s):  
Mass Spectrometry ◽  
Combinatorial Chemistry ◽  
Mass Spectra ◽  
Organic Molecules ◽  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Negative Ion ◽  
Phase Synthesis ◽  
Secondary Ion ◽  
Mass Spectrometry Application

ABSTRACTIn combinatorial chemistry, most libraries are prepared according to solid-phase synthesis strategies using resins or pins. Although synthesis and purification steps are facilitated, reaction monitoring presents difficulties. Since the polymeric support is not soluble, an analytical method able to cope with a solid sample is thus required to perform direct identification of the anchored molecules without any chemical treatment. Static-Secondary Ion Mass Spectrometry (S-SIMS) was investigated in that purpose. Positive and negative ion mass spectra were acquired to identify single beads whereas mixtures (Mix and Split libraries or pooled beads issued from different batches) were profiled through imaging experiments.

Mass Spectrometric Behaviour of Carboxylated Polyethylene Glycols and Carboxylated Octylphenol Ethoxylates

2003 ◽  
Vol 9 (3) ◽  
pp. 165-173 ◽  
Author(s):  
Magdalena Frańska ◽  
Agnieszka Zgoła ◽  
Joanna Rychłowska ◽  
Andrzej Szymański ◽  
Zenon Łukaszewski ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Alkali Metal ◽  
Mass Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Metal Cations ◽  
Mass Spectrometric ◽  
Polyethylene Glycols ◽  
Alkali Metal Cations ◽  
Secondary Ion

The mass spectrometric behaviour of mono- and di-carboxylated polyethylene glycols (PEGCs and CPEGCs) and carboxylated octylphenol ethoxylates (OPECs) is discussed. The tendency for ionisation (deprotonation, protonation and cationisation by alkali–metal cations) of carboxylated PEGs was compared with that of non-carboxylated analogues by using both secondary-ion mass spectrometry (SIMS) and electrospray ionisation (ESI). The fragmentation of the PEGCs and CPEGCs is discussed and also compared with their neutral analogues, PEGs. B/E linked-scan mass spectra were recorded, using secondary-ion mass spectrometry as a method for ion generation, for deprotonated and protonated molecules as well as for molecules cationised by alkali–metal cations. The fragmentation behaviour of PEGs is found to be different from that of CPEGCs, The presence of carboxyl groups may be confirmed not only by the determination of molecular weights of the ethoxylates studied, but also on the basis of the fragment ions formed. The metastable decomposition of the [OPEC-H]− ions proceeds through the cleavage of the bond between the octylphenol moiety and the ethoxylene chain and leads to the octylphenoxyl anions. It permits determination of the mass of the hydrophobic moiety of the studied carboxylated alkylphenol ethoxylate. ESI mass spectra recorded in the negative-ion mode were found to be more suitable than SI mass spectra for the determination of the average molecular weight of carboxylated ethoxylates.

Liquid Secondary Ion Mass Spectrometry and Collision-induced Dissociation Mass Spectrometry of Sulfonamide Derivatives of meso-Tetraphenylporphyrin

1999 ◽  
Vol 03 (03) ◽  
pp. 172-179 ◽  
Author(s):  
M. ROSÁRIO M. DOMINGUES ◽  
M. GRAÇA SANTANA-MARQUES ◽  
A. J. FERRRER-CORREIA ◽  
AUGUSTO C. TOMÉ ◽  
MARIA G. P. M. S. NEVES ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Ions ◽  
Collision Induced Dissociation ◽  
Fragment Ions ◽  
Ion Mass Spectrometry ◽  
Derivatives Of ◽  
Secondary Ion

Liquid secondary ion mass spectrometry (LSIMS) and collision-induced dissociation (CID) were used for the characterization of sulfonamide derivatives of meso-tetraphenylporphyrin (TPP). The spectra obtained using LSIMS show abundant molecular ions and fragment ions from losses of the sulfonamide moieties. The main fragmentation observed in the LSI mass spectra and in the CID spectra of the protonated or cationized molecules involves the loss of one sulfonamide group. In addition, in the CID spectra of these compounds the fragment ions formed by the elimination of two, three and/or four sulfonamide groups are also observed. The CID spectra of the protonated or cationized molecules of these derivatives do not display the ions formed by the cleavage of the S - N bond which have been reported for other sulfonamide compounds. The LSI mass spectra and CID spectra of sulfonamide derivatives of meso-tetraphenylporphyrin provide an easy and reliable means of identification of the number and nature of sulfonamide groups in the porphyrinic ring.

Ohmic Contact Formation Mechanism in the Ge/Pd/N-GaAs System

1989 ◽  
Vol 148 ◽  
Author(s):  
E.D. Marshall ◽  
S.S. Lau ◽  
C.J. Palmstrøm ◽  
T. Sands ◽  
C.L. Schwartz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Solid Phase ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Solid Phase Regrowth ◽  
Ohmic Contact Formation ◽  
Secondary Ion

ABSTRACTAnnealed Ge/Pd/n-GaAs samples utilizing substrates with superlattice marker layers have been analyzed using high resolution backside secondary ion mass spectrometry and cross-sectional transmission electron microscopy. Interfacial compositional and microstructural changes have been correlated with changes in contact resistivity. The onset of good ohmic behavior is correlated with the decomposition of an intermediate epitaxial Pd4(GaAs,Ge2) phase and solid-phase regrowth of Ge-incorporated GaAs followed by growth of a thin Ge epitaxial layer.

Negative ion liquid secondary ion mass spectrometry of carbamate-linked oligodeoxynucleosides. II

1990 ◽  
Vol 25 (4) ◽  
pp. 219-224 ◽  
Author(s):  
James A. Laramée ◽  
Brian Arbogast ◽  
Eugene P. Stirchak ◽  
Dwight D. Weller ◽  
Max L. Deinzer
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Negative Ion ◽  
Ion Mass Spectrometry ◽  
Secondary Ion
Sign in / Sign up

Export Citation Format

Share Document