Method of MS Mass Spectrometry
AssigneeMicromass UK Limited
InventorsJeffery Mark Brown, Martin Raymond Green
Life of this patent
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Abstract
A method of mass spectrometry is disclosed comprising alternating between a first mode in which parent ions are analysed and a second mode in which parent ions are fragmented and their fragment ions are mass analysed. In the first mode the parent ions are charge reduced before being analysed, so as to simplify the parent ion spectral data obtained. In the second mode, the parent ions are not charge reduced prior to fragmentation, so that it remains relatively easy to induce the parent ions to fragment. The parent ions are then associated with their fragment ions using the mass spectral data obtained.
Claims22
A method of mass spectrometry comprising:
- (i) providing a plurality of parent ions;
- (ii) reducing a charge state of parent ions by subjecting the parent ions to charge reduction conditions, and mass analysing the resulting charge reduced parent ions so as to obtain first mass spectral data;
- (iii) fragmenting parent ions to produce fragment ions without having first reduced the charge state of the parent ions by exposing the ions to said charge reduction conditions, and mass analysing said fragment ions to obtain second mass spectral data;
- (iv) wherein the parent ions are alternately and repeatedly subjected to said charge reduction conditions and said fragmenting so that the method repeatedly alternates between steps (ii) and (iii);
- and
- wherein the method comprises associating parent ions detected in said first mass spectral data with fragment ions detected in said second mass spectral data.
(canceled)
A mass spectrometer comprising:
- a device arranged and adapted to reduce a charge state of ions;
- a mass analyser;
- a fragmentation device;
- and
- control means arranged and adapted to:
- reduce a charge state of parent ions in said device arranged and adapted to reduce the charge state of ions by subjecting the parent ions to charge reduction conditions;
- mass analyse resulting charge reduced parent ions in said mass analyser so as to obtain first mass spectral data;
- fragment parent ions in said fragmentation device so as to produce fragment ions without having first reduced the charge state of the parent ions by exposing the ions to said charge reduction conditions;
- mass analyse said fragment ions in said mass analyser so as to obtain second mass spectral data;
- repeatedly alternate between reducing the charge of the parent ions and fragmenting the parent ions;
- and
- associate parent ions detected in said first mass spectral data with fragment ions detected in said second mass spectral data.
(canceled)
A method of mass spectrometry comprising:
- generating a plurality of species of parent ions;
- charge reducing the parent ions;
- varying an intensity profile of one or more species of charge reduced parent ions as a function of time so that different species of parent ions are caused to have different intensity profiles as a function of time;
- fragmenting parent ions without subjecting the parent ions to the charge reduction step so as to form fragment ions;
- mass analysing the fragment ions;
- and
- correlating the fragment ions with corresponding charge reduced parent ions based on the intensity profiles of said fragment ions and the intensity profiles of said charge reduced parent ions.
A mass spectrometer comprising:
- an ion source for generating a plurality of species of parent ions;
- means for charge reducing the parent ions;
- means for varying the intensity profile of one or more species of charge reduced parent ions as a function of time so that different species of parent ions are caused to have different intensity profiles as a function of time;
- means for fragmenting parent ions without subjecting the parent ions to the means for charge reduction so as to form fragment ions;
- means for mass analysing the fragment ions;
- and
- means for correlating the fragment ions with corresponding charge reduced parent ions based on the intensity profiles of said fragment ions and the intensity profiles of said charge reduced parent ions.
Dependencies are inferred from the claim text.