Patent ID: 7388194

Claim:
A method of quantitatively detecting sample molecules, comprising: providing an ion source having a target surface carrying a sample material; and performing measurements on one or more sample areas on the target surface, by performing the following steps for each sample area: operating a laser to apply laser light to said each sample area on the target source for a total irradiation duration to generate analyte ions from the sample material on the target surface, the total irradiation duration being set to be significantly shorter than a time required to deplete the sample material in said each sample area on the target source; collisionally damping the analyte ions with a damping gas; passing the collisionally damped analyte ions into a mass analyzer operated in a multiple-reaction monitoring mode to select ions of a precursor type derived from the sample material and ions of a product type created by fragmenting ions of the precursor type; and detecting ions of the product type selected by the mass analyzer.