Efficiency of Gas-Phase Ion Formation in Matrix-Assisted Laser Desorption Ionization with 2,5-Dihydroxybenzoic Acid as Matrix

Efficiency of Gas-Phase Ion Formation in Matrix-Assisted Laser Desorption Ionization with 2,5-Dihydroxybenzoic Acid as Matrix

Numbers of matrixand analyte-derived ions and their sum in matrix-assisted laser desorption ionization (MALDI) of a peptide were measured using 2,5-dihydroxybenzoic acid (DHB) as matrix. As for MALDI with α-cyano-4-hydroxy cinnamic acid as matrix, the sum was independent of the peptide concentration in the solid sample, or was the same as that of pure DHB. This suggested that the matrix ion was...

Competing ion decomposition channels in matrix-assisted laser desorption ionization.

We gauged the internal energy transfer for two dissociative ion decomposition channels in matrix-assisted laser desorption ionization (MALDI) using the benzyltriphenylphosphonium (BTP) thermometer ion [PhCH 2PPh 3] (+). Common MALDI matrixes [alpha-cyano-4-hydroxycinnamic acid (CHCA), 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid, SA), and 2,5-dihydroxycinnamic acid (DHB)] were studied w...

Solid-phase thermodynamic interpretation of ion desorption in matrix-assisted laser desorption/ionization.

This work demonstrates a quantitative interpretation of ion desorption in matrix-assisted laser desorption/ionization (MALDI). The theoretical modeling incorporates transition state theory for the desorption of surface ions, assuming chemical and thermal equilibrium in the solid state prior to desorption. It is distinct from conventional models that assume chemical equilibrium in the gas phase....

Desorption/ionization efficiency of peptides containing disulfide bonds in matrix-assisted laser desorption/ionization mass spectrometry.

In order to elucidate the role of desorption/ionization efficiency of peptides in MALDI-MS, we focused on peptides with disulfide bonds, which form a rigid tertiary structure. We synthesized seven sets of peptides with one disulfide bond (oxytocin, somatostatin, [Arg(8)]-vasopressin, [Arg(8)]-vasotocin, cortistatin, melanin-concentrating hormone, urotensin II-related peptide) and five sets of ...

Matrix-Assisted Laser Desorption/Ionization (MALDI)