THE GAS-PHASE BASICITIES OF MATRIX-ASSISTED-LASER-DESORPTION IONIZATION MATRICES/

The gas-phase basicities of three common matrices used in matrix-assis ted laser desorption/ionization (MALDI) have been investigated using l aser desorption with Fourier transform ion cyclotron resonance (FT-ICR ) mass spectrometry. In bracketing type experiments, laser-desorbed io ns from 2,5-dihydroxy-benzoic acid, alpha-cyano-4-hydroxy-cinnamic aci d and sinapic acid were tested for their ability to protonate test sub stances, This study was not limited to protonated matrix species but a lso included prominent fragments.