RATIONALE Detection of hydrophobic peptides remains a major obstacle for matrix‐
assisted laser desorption/ionization mass spectrometry (MALDI‐MS). This stems from the
fact that most matrices for MALDI are hydrophilic and therefore have low affinities for
hydrophobic peptides. Herein, 1‐aminopyrene (AP) and AP‐derived group of uniform
materials based on organic salts (GUMBOS) as novel matrices for MALDI‐MS analyses of
peptides were investigated for hydrophobic and hydrophilic peptides. METHODS A number …

METHODS: A number of solid-phase AP-based GUMBOS are synthesized with variable
hydrophobicity simply by changing the counterions. Structures were confirmed by use of 1H
NMR and electrospray ionization mass spectrometry (ESI-MS). 1-Octanol/water partition
coefficients (Ko/w) were used to measure the hydrophobicity of the matrices. A dried-droplet
method was used for sample preparation. All spectra were obtained using a MALDI-TOF
mass spectrometer in positive ion reflectron mode. RESULTS: A series of AP-based …