Iodine-assisted matrix-assisted laser desorption/ionisation

Addition of iodine to the matrix has been found to lead to lower thresholds for ion formation in matrix-assisted laser desorption/ionisation (MALDI) of peptides and other compounds. Intensities of ions from the matrix have been suppressed through the addition of iodine to the matrix; intensities of ions corresponding to addition of sodium or potassium to the analyte have been diminished. These effects have been observed with a number of matrices, including 2,5-dihydroxybenzoic acid, dithranol and alpha-cyano-4-hydroxy-cinnamic acid