Abstract: A method of mass spectrometry or ion mobility spectrometry is disclosed wherein a sample is ionized by an electrified sprayer so as to produce multiply charged analyte ions of a first polarity in gas-phase. A reaction region is provided downstream of the electrified sprayer, wherein the reaction region is maintained substantially at atmospheric pressure and is maintained substantially free of electric-fields. A gas flow is provided from said electrified sprayer to said reaction region such that the gas flow carries the analyte ions from the electrified sprayer into the reaction region. Free electrons or reagent ions of a second polarity are generated in the reaction region, wherein the second polarity is opposite to said first polarity. The free electrons or reagent ions are then reacted with the analyte ions in the reaction region so as to reduce the charge state of the multiply charged analyte ions and thereby produce charge-reduced analyte ions.

Abstract: A method of mass spectrometry or ion mobility spectrometry is disclosed wherein a sample is ionised by an electrified sprayer so as to produce multiply charged analyte ions of a first polarity in gas-phase. A reaction region is provided downstream of the electrified sprayer, wherein the reaction region is maintained substantially at atmospheric pressure and is maintained substantially free of electric-fields. A gas flow is provided from said electrified sprayer to said reaction region such that the gas flow carries the analyte ions from the electrified sprayer into the reaction region. Free electrons or reagent ions of a second polarity are generated in the reaction region, wherein the second polarity is opposite to said first polarity. The free electrons or reagent ions are then reacted with the analyte ions in the reaction region so as to reduce the charge state of the multiply charged analyte ions and thereby produce charge-reduced analyte ions.

Abstract: A method of mass spectrometry is disclosed comprising providing a mixture of different analyte ions and supplying electrons or reagent ions to said mixture so as to transfer charge to the analyte ions. The transfer of charge causes at least some of the analyte ions to dissociate and others of the analyte ions not to dissociate, but to form intermediate ions of altered charge state. These intermediate ions are then isolated from other ions and excited so as to dissociate into daughter ions. The intermediate ions and their daughter ions are analyzed and associated with each other so that the intermediate can be identified from their daughter ions. The analyte ions can then be identified from the intermediate ions, since they differ only in charge state. The disclosed method enables analyte ions to be associated with their fragment ions, and therefore identified, without having to isolate individual analyte ions prior to their interactions with the electrons or reagent ions.

Abstract: A method of mass spectrometry is disclosed comprising providing a mixture of different analyte ions and supplying electrons or reagent ions to said mixture so as to transfer charge to the analyte ions. The transfer of charge causes at least some of the analyte ions to dissociate and others of the analyte ions not to dissociate, but to form intermediate ions of altered charge state. These intermediate ions are then isolated from other ions and excited so as to dissociate into daughter ions. The intermediate ions and their daughter ions are analysed and associated with each other so that the intermediate can be identified from their daughter ions. The analyte ions can then be identified from the intermediate ions, since they differ only in charge state. The disclosed method enables analyte ions to be associated with their fragment ions, and therefore identified, without having to isolate individual analyte ions prior to their interactions with the electrons or reagent ions.