Mass spectrometry with selective ion filtration by digital thresholding
First Claim
Patent Images
1. A method of identifying a multiply-charged ion comprising:
- a) specifying a digital signal threshold on a mass spectrometer, wherein the mass spectrometer comprises;
i) an ion detector;
ii) a digitizer for converting an analog signal to a digital signal;
iii) an analog signal transfer means for transferring an analog signal from the detector to the digitizer; and
iv) a digital threshold filter, for setting a digital signal threshold, in digital data communication with the digitizer, in response to a digital signal input from the digitizer, independently outputting a digital signal to a data file only if the digital signal input is greater than the specified digital signal threshold;
wherein upon a mass spectrometer measurement of the multiply-charged ion, the filtered digital signal output to the data file originates from the detection of the multiply-charged ion and excludes digital signal output from analog signals arising from singly-charged ions.
0 Assignments
0 Petitions
Accused Products
Abstract
The methods described herein generally relate to characterization of large analytes, such as biomolecules, by molecular mass analysis. Specifically, the methods are directed to molecular mass analysis of singly- or multiply-charged ions by selective ion filtering carried out by a digital thresholding process.
-
Citations
32 Claims
-
1. A method of identifying a multiply-charged ion comprising:
-
a) specifying a digital signal threshold on a mass spectrometer, wherein the mass spectrometer comprises; i) an ion detector; ii) a digitizer for converting an analog signal to a digital signal; iii) an analog signal transfer means for transferring an analog signal from the detector to the digitizer; and iv) a digital threshold filter, for setting a digital signal threshold, in digital data communication with the digitizer, in response to a digital signal input from the digitizer, independently outputting a digital signal to a data file only if the digital signal input is greater than the specified digital signal threshold; wherein upon a mass spectrometer measurement of the multiply-charged ion, the filtered digital signal output to the data file originates from the detection of the multiply-charged ion and excludes digital signal output from analog signals arising from singly-charged ions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for determining the molecular mass of a plurality of analytes in a mixture comprising:
-
a) specifying a unique digital signal threshold for at least some members of a plurality of digital threshold filters on a mass spectrometer, wherein the mass spectrometer comprises; i) an ion detector; ii) a digitizer for converting an analog signal to a digital signal; iii) an analog signal transfer means for transferring an analog signal from the detector to the digitizer; and iv) a plurality of digital threshold filters for setting a digital signal threshold in digital data communication with the digitizer, in response to a digital signal input from the digitizer independently outputting a digital signal to a corresponding data file only if the digital signal input is greater than the specified digital signal threshold; b) making a mass spectrometer measurement of the mixture, wherein each unique digital signal threshold differentially filters digital signals arising from the plurality of analytes and produces a unique digital signal output to each corresponding data file wherein the measurement results in storage of a plurality of data files; and c) analyzing each member of the plurality of data files wherein the molecular mass of at least one member of the plurality of analytes is contained therein. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A method of calibrating a mass spectrum of an analyte comprising:
-
a) specifying a first digital signal threshold at a first member of a plurality of digital threshold filters, on a mass spectrometer, wherein the mass spectrometer comprises; i) an ion detector; ii) a digitizer for converting an analog signal to a digital signal; iii) an analog signal transfer means for transferring an analog signal from the detector to the digitizer; and iv) a plurality of digital threshold filters for setting a digital signal threshold, in digital data communication with the digitizer, in response to a digital signal input from the digitizer, independently outputting a digital signal to a corresponding data file only if the digital signal input is greater than the specified digital signal threshold; wherein the first digital signal threshold is specified such that digital signal output to a first data file comprises signals from the analyte and a calibrant ion; b) specifying a second digital signal threshold at a second member of the plurality of digital threshold filters wherein the second digital signal threshold is specified such that digital signal output to a second data file comprises signals from the analyte but not from the calibrant ion; c) subtracting the second data file from the first data file to obtain a calibration data file comprising a signal from the calibrant ion but not from the analyte; and d) using said calibration data file to calibrate the mass spectrum of the analyte. - View Dependent Claims (24, 25, 26, 27, 28, 29)
-
-
30. A system comprising a mass spectrometer comprising:
-
an ion detector; a digitizer for converting an analog signal to a digital signal; an analog signal transfer means for transferring an analog signal from the detector to the digitizer; a plurality of digital threshold filters for setting a plurality of independent digital signal thresholds, each digital threshold filter in parallel electronic communication with the digitizer, each digital threshold filter in response to a digital voltage input from the digitizer independently outputting a digital voltage only if the digital voltage input is greater than the specified digital signal threshold; a plurality of data files; and a plurality of parallel digital signal output transferring means, each of which is in digital data communication with one of the digital threshold filters and a corresponding data file from the plurality of data files. - View Dependent Claims (31, 32)
-
Specification