Patent ID: 8044346

Claim:
A method for ionizing analyte-containing sample lying on a surface of a substrate, comprising: directing to the sample a heated flow of desorption gas in order to desorb analyte from the surface, the desorption gas comprising a mixture of solvent-free nebulizing gas and solvent vapor, and simultaneously directing to the sample light capable of ionizing the desorbed analyte in the presence of the desorption gas, wherein said desorption gas is produced and directed to the sample by feeding a liquid solvent and a nebulizer gas to a nebulizer, in the nebulizer, vaporizing the liquid solvent by heating to a target temperature above the vaporizing temperature of the solvent, directing the heated solvent vapor through an outlet of the nebulizer to the sample using a stream of the nebulizing gas, whereby said heating is strong enough to produce desorption gas essentially free of solvent droplets, and the ionization of the analyte takes place at least partly indirectly through ionization of the solvent vapor by said light.