Patent ID: 9613785
Date: 2017-04-04
CPC Classifications: G01N,H01J

Claim:
1. A method of mass spectrometry comprising the steps of: providing a sample; performing a method of analysis of parent analyte ions and fragment ions from a first area of the sample, comprising the steps of: exciting a first spot in the first area of the sample to produce a first set of parent analyte ions; determining quantities and mass to charge ratios of at least some of the ions in the first set of parent analyte ions; exciting a second spot in the first area of the sample to produce a 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 quantities and mass to charge ratios of at least some of the ions in the set of fragment ions from the second set of parent analyte ions; performing the method of analysis for at least a second area of the sample; identifying changes in the quantity of a parent analyte ion in the first area and at least the second area and changes in the quantity of at least one fragment ion in the first area and at least the second area; and identifying at least one ion from the set of fragment ions for which the changes in the quantity of any parent analyte ions in the first area and at least the second area do not correspond with changes in the quantity of the at least one fragment ion in the first area and at least the second area thereby providing an indication of potential parent analyte ions which are isomers or other parent ions of the same mass to charge ratio.