Patent ID: 8895917

Claim:
A method of mass spectrometry comprising the steps of: providing a sample; performing a method of association of parent analyte ions from a first area of the sample with fragment ions from the first area of the sample comprising the steps of: exciting a first spot in the first area on the surface of the sample to produce a first set of parent analyte ions; determining the mass to charge ratio of at least some of the ions from the first set of parent analyte ions as a function of ion mobility of the ions; exciting a second spot in the first area on the surface to produce a second set of parent analyte ions; determining the ion mobility of at least some of the ions of the second set of parent analyte ions; fragmenting at least a portion of the second set of parent analyte ions to produce a set of fragment ions; determining the mass to charge ratio of at least some of the ions from the set of fragment ions as a function of the ion mobility of the ions from the second set of parent analyte ions; associating the set of fragment ions with the first set of parent analyte ions by comparison of the ion mobility of the ions from the first set of parent analyte ions with the ion mobility of the ions from the second set of parent analyte ions associated with the fragment ions; performing the method of association for at least a second area of the sample; and assigning at least one ion from the set of fragment ions to an ion in the first set of parent analyte ions by identifying changes between the quantity of a parent analyte ion in the first area and at least the second area and corresponding changes in the quantity of at least one fragment ion in the first area and at least the second area.