Mass spectrometer

A method of mass spectrometry comprising:

• passing parent or precursor ions from a first sample to a collision, fragmentation or reaction device;
• repeatedly switching, altering or varying said collision, fragmentation or reaction device between a first mode wherein at least some of said parent or precursor ions from said first sample are fragmented or reacted into one or more fragment, product, daughter or adduct ions and a second mode wherein substantially fewer parent or precursor ions are fragmented or reacted;
• passing parent or precursor ions from a second sample to a collision, fragmentation or reaction device;
• repeatedly switching, altering or varying said collision, fragmentation or reaction device between a first mode wherein at least some of said parent or precursor ions from said second sample are fragmented or reacted into one or more fragment, product, daughter or adduct ions and a second mode wherein substantially fewer parent or precursor ions are fragmented or reacted;
• recognising first parent or precursor ions of interest from said first sample;
• automatically determining the intensity of said first parent or precursor ions of interest, said first parent or precursor ions of interest having a first mass to charge ratio;
• automatically determining the intensity of second parent or precursor ions from said second sample which have said same first mass to charge ratio;
• determining a first ratio of the intensity of said first parent or precursor ions of interest to the intensity of other parent or precursor ions in said first sample;
• determining a second ratio of the intensity of said second parent or precursor ions to the intensity of other parent or precursor ions in said second sample;
• and
• comparing said first ratio with said second ratio;
• and
• wherein said collision, fragmentation or reaction device is selected from the group consisting of:
• (i) a Surface Induced Dissociation (“SID”) fragmentation device;
• (ii) an Electron Transfer Dissociation fragmentation device;
• (iii) an Electron Capture Dissociation fragmentation device;
• (iv) an Electron Collision or Impact Dissociation fragmentation device;
• (v) a Photo Induced Dissociation (“PID”) fragmentation device;
• (vi) a Laser Induced Dissociation fragmentation device;
• (vii) an infrared radiation induced dissociation device;
• (viii) an ultraviolet radiation induced dissociation device;
• (ix) a nozzle-skimmer interface fragmentation device;
• (x) an in-source fragmentation device;
• (xi) an ion-source Collision Induced Dissociation fragmentation device;
• (xii) a thermal or temperature source fragmentation device;
• (xiii) an electric field induced fragmentation device;
• (xiv) a magnetic field induced fragmentation device;
• (xv) an enzyme digestion or enzyme degradation fragmentation device;
• (xvi) an ion-ion reaction fragmentation device;
• (xvii) an ion-molecule reaction fragmentation device;
• (xviii) an ion-atom reaction fragmentation device;
• (xix) an ion-metastable ion reaction fragmentation device;
• (xx) an ion-metastable molecule reaction fragmentation device;
• (xxi) an ion-metastable atom reaction fragmentation device;
• (xxii) an ion-ion reaction device for reacting ions to form adduct or product ions;
• (xxiii) an ion-molecule reaction device for reacting ions to form adduct or product ions;
• (xxiv) an ion-atom reaction device for reacting ions to form adduct or product ions;
• (xxv) an ion-metastable ion reaction device for reacting ions to form adduct or product ions;
• (xxvi) an ion-metastable molecule reaction device for reacting ions to form adduct or product ions;
• and (xxvii) an ion-metastable atom reaction device for reacting ions to form adduct or product ions.

A mass spectrometer comprising:

• a collision, fragmentation or reaction device which is arranged and adapted to be repeatedly switched in use between a first mode wherein at least some parent or precursor ions are fragmented or reacted into one or more fragment, product, daughter or adduct ions and a second mode wherein substantially fewer parent or precursor ions are fragmented or reacted;
• a mass analyser;
• and
• a control system which in use:
• (i) recognises first parent or precursor ions of interest from a first sample, said first parent or precursor ions of interest having a first mass to charge ratio;
• (ii) determines the intensity of said first parent or precursor ions of interest;
• (iii) determines the intensity of second parent or precursor ions from a second sample which have said same first mass to charge ratio;
• and
• (iv) compares the intensity of said first parent or precursor ions of interest with the intensity of said second parent or precursor ions;
• wherein said collision, fragmentation or reaction device is selected from the group consisting of:
• (i) a Surface Induced Dissociation (“SID”) fragmentation device;
• (ii) an Electron Transfer Dissociation fragmentation device;
• (iii) an Electron Capture Dissociation fragmentation device;
• (iv) an Electron Collision or Impact Dissociation fragmentation device;
• (v) a Photo Induced Dissociation (“PID”) fragmentation device;
• (vi) a Laser Induced Dissociation fragmentation device;
• (vii) an infrared radiation induced dissociation device;
• (viii) an ultraviolet radiation induced dissociation device;
• (ix) a nozzle-skimmer interface fragmentation device;
• (x) an in-source fragmentation device;
• (xi) an ion-source Collision Induced Dissociation fragmentation device;
• (xii) a thermal or temperature source fragmentation device;
• (xiii) an electric field induced fragmentation device;
• (xiv) a magnetic field induced fragmentation device;
• (xv) an enzyme digestion or enzyme degradation fragmentation device;
• (xvi) an ion-ion reaction fragmentation device;
• (xvii) an ion-molecule reaction fragmentation device;
• (xviii) an ion-atom reaction fragmentation device;
• (xix) an ion-metastable ion reaction fragmentation device;
• (xx) an ion-metastable molecule reaction fragmentation device;
• (xxi) an ion-metastable atom reaction fragmentation device;
• (xxii) an ion-ion reaction device for reacting ions to form adduct or product ions;
• (xxiii) an ion-molecule reaction device for reacting ions to form adduct or product ions;
• (xxiv) an ion-atom reaction device for reacting ions to form adduct or product ions;
• (xxv) an ion-metastable ion reaction device for reacting ions to form adduct or product ions;
• (xxvi) an ion-metastable molecule reaction device for reacting ions to form adduct or product ions;
• and (xxvii) an ion-metastable atom reaction device for reacting ions to form adduct or product ions.

A mass spectrometer comprising:

• a collision, fragmentation or reaction device repeatedly switched in use between a first mode wherein at least some parent or precursor ions are fragmented or reacted into one or more fragment, product, daughter or adduct ions and a second mode wherein substantially fewer parent or precursor ions are fragmented or reacted;
• a mass analyser;
• and
• a control system which in use:
• (i) recognises first parent or precursor ions of interest from a first sample, said first parent or precursor ions of interest having a first mass to charge ratio;
• (ii) determines the intensity of said first parent or precursor ions of interest;
• (iii) determines the intensity of second parent or precursor ions from a second sample which have said same first mass to charge ratio;
• (iv) determines a first ratio of the intensity of said first parent or precursor ions of interest to the intensity of other parent or precursor ions in said first sample;
• (v) determines a second ratio of the intensity of said second parent or precursor ions to the intensity of other parent or precursor ions in said second sample;
• and
• (vi) compares said first ratio with said second ratio;
• wherein said collision, fragmentation or reaction device is selected from the group consisting of:
• (i) a Surface Induced Dissociation (“SID”) fragmentation device;
• (ii) an Electron Transfer Dissociation fragmentation device;
• (iii) an Electron Capture Dissociation fragmentation device;
• (iv) an Electron Collision or Impact Dissociation fragmentation device;
• (v) a Photo Induced Dissociation (“PID”) fragmentation device;
• (vi) a Laser Induced Dissociation fragmentation device;
• (vii) an infrared radiation induced dissociation device;
• (viii) an ultraviolet radiation induced dissociation device;
• (ix) a nozzle-skimmer interface fragmentation device;
• (x) an in-source fragmentation device;
• (xi) an ion-source Collision Induced Dissociation fragmentation device;
• (xii) a thermal or temperature source fragmentation device;
• (xiii) an electric field induced fragmentation device;
• (xiv) a magnetic field induced fragmentation device;
• (xv) an enzyme digestion or enzyme degradation fragmentation device;
• (xvi) an ion-ion reaction fragmentation device;
• (xvii) an ion-molecule reaction fragmentation device;
• (xviii) an ion-atom reaction fragmentation device;
• (xix) an ion-metastable ion reaction fragmentation device;
• (xx) an ion-metastable molecule reaction fragmentation device;
• (xxi) an ion-metastable atom reaction fragmentation device;
• (xxii) an ion-ion reaction device for reacting ions to form adduct or product ions;
• (xxiii) an ion-molecule reaction device for reacting ions to form adduct or product ions;
• (xxiv) an ion-atom reaction device for reacting ions to form adduct or product ions;
• (xxv) an ion-metastable ion reaction device for reacting ions to form adduct or product ions;
• (xxvi) an ion-metastable molecule reaction device for reacting ions to form adduct or product ions;
• and (xxvii) an ion-metastable atom reaction device for reacting ions to form adduct or product ions.