Characterization of two new matrices for matrix-assisted laser desorption/ionization mass spectrometry

Three structurally related compounds, 4-hydroxy-33-methoxyphenylpyruvic acid (HMPPA), indole-3 pyruvic acid (IPA), and indole-3-glyoxylic acid have been evaluated as matrix-assisted laser desorption/ionization (MALDI) matrices. HMPPA and IPA were found to be effective matrices for MALDI-MS analysis of proteins and peptides and have been characterized in this work. HMPPA was found to be a particularly good matrix for the analysis of proteins and peptides because of its tolerance towards impurities and the resulting sensitivity in MALDI-MS experiments. Analysis of model proteins and peptides, including those in biological fluid, are demonstrated.