Patent ID: 7511267
Filing Date: 2009-03-31
Classification: H01J

Abstract:
1. A method of performing neutral-loss analysis of sample ions in a hybrid mass spectrometer having a first mass analyzer and a second mass analyzer, the second mass analyzer being capable of acquiring mass spectra at high resolution and mass accuracy, the method comprising steps of: (a) acquiring an MS spectrum of the sample ions to identify at least one precursor ion of interest; (b) fragmenting the at least one precursor ion of interest to yield product ions, and acquiring an MS/MS spectrum of the product ions at the first mass analyzer; (c) identifying at least one candidate product ion having a mass that differs from the corresponding precursor ion species by a nominal neutral loss value; (d) acquiring a mass spectrum of the sample ions at the second mass analyzer; (e) acquiring an MS/MS spectrum at the second mass analyzer of product ions produced by fragmenting the precursor ion corresponding to the at least one candidate product ion species, and determining, based on the MS and MS/MS spectra obtained at the second analyzer, whether the accurate mass difference between the at least one candidate product ion species and the corresponding precursor ion species matches an accurate neutral loss value; and (f) acquiring or processing an MS