laser desorption electrospray ionisation matrix-assisted laser desorption electrospray ionisation An ionisation method where neutral molecules are desorbed from the sample (usually biological and held in an organic acid matrix) using a nitrogen laser and then ionised by collision with charged solvent droplets which are formed by forcing the solvent through a small heated capillary (at a flow rate of 1–10 L min-1) into an electric field. MALDESI matrix-assisted laser desorption electrospray ionization CHMO:0001662