Patent ID: 8748809

Claim:
A method of obtaining and analyzing a chromatography/mass spectrometry spectrum of a sample comprising at least two components, characterized by: a) setting a current value of a first energy level and a current value of a second energy level; b) separating the components of the sample using a chromatographic column; c) ionizing a portion of the separated components so as create precursor ions; d) introducing a first portion of the precursor ions into a collision or reaction cell so as to generate a first sub-population of ions corresponding to the first energy level; e) introducing a second portion of the precursor ions into the same or a different collision or reaction cell so as to generate a second sub-population of ions corresponding to the second energy level; f) transferring a mixture of the first sub-population of ions and the second sub-population of ions into a mass analyzer; g) producing a mass-to-charge analysis of the ions of the mixture of the first and second sub-populations of ions using the mass analyzer; h) expelling the first and second sub-populations of ions from the mass analyzer; i) varying the current value of at least one of the first and the second energy levels according to a pre-determined cyclical variation of energy; j) repeating steps c) through g); and k) producing an analysis of a time-variation of the mass-to-charge analysis.