Systems and methods for charge state assignment in mass spectrometry
A method for assigning charge state in mass spectrometry includes receiving a detector response signal corresponding to a plurality of ion arrival events. The detector response signal includes information related to individual ion responses generated by a detector for each ion arrival event. Detector response profiles are generated for mass-to-charge (m/z) bins of a mass spectrum generated from the ion arrival events based on the detector response signal. The m/z bins are grouped into a plurality of groups based on a similarity of the detector response profiles of the m/z bins. A charge state is assigned to one or more features based on the groups of m/z bins.
1 . A method for assigning charge state in mass spectrometry, the method comprising:
receiving a detector response signal corresponding to a plurality of ion arrival events, the detector response signal comprising information related to individual ion responses generated by a detector for each ion arrival event;
based on the detector response signal, generating detector response profiles for mass-to-charge (m/z) bins of a mass spectrum generated from the ion arrival events;
grouping the m/z bins into a plurality of groups based on a similarity of the detector response profiles of the m/z bins; and
assigning a charge state to one or more features based on the groups of m/z bins.
2 . The method of claim 1 , further comprising generating a simplified mass spectra based on the groups of m/z bins, wherein the groups of m/z bins are indicated in the simplified mass spectra.
3 . The method of claim 1 , further comprising calculating a mass corresponding to the ion arrival events based on the assigned charge state.
4 . The method of claim 1 , wherein grouping the m/z bins is further based on additional separation domain data.
5 . The method of claim 4 , wherein the additional separation domain data includes at least one of retention time, drift time, or compensation voltage for ion mobility.
6 . The method of claim 1 , wherein grouping the m/z bins is performed using a principal component analysis (PCA), a k-means clustering algorithm, or a principal component variable grouping (PCVG) algorithm.
7 . The method of claim 1 , further comprising generating a representation of the ion arrival events, the representation having an m/z dimension, a detector response dimension, and an ion count or probability dimension.
8 . The method of claim 7 , wherein the representation is a heatmap.
9 . The method of claim 7 , wherein grouping the m/z bins is performed, at least in part, by applying a pattern recognition algorithm to the representation.
10 . A system for assigning charge state in mass spectrometry, the system comprising:
a detector to configured to generate a detector response signal for each ion arrival event;
a processor; and
a memory storing instructions that are configured to, when executed by the processor, cause the system to perform a set of operations comprising:
receiving, from the detector, the detector response signal corresponding to a plurality of ion arrival events, the detector response signal comprising information related to individual ion responses generated by the detector for each ion arrival event;
based on the detector response signal, generating detector response profiles for mass-to-charge (m/z) bins of a mass spectrum generated from the ion arrival events;
grouping the m/z bins into a plurality of groups based on a similarity of the detector response profiles of the m/z bins; and
assigning a charge state to one or more features based on the groups of m/z bins.
11 . The system of claim 10 , wherein the operations further comprise generating a simplified mass spectra based on the groups of m/z bins, wherein the groups of m/z bins are indicated in the simplified mass spectra.
12 . The system of claim 10 , wherein grouping the m/z bins is further based on additional separation domain data.
13 . The system of claim 12 , wherein the additional separation domain data includes at least one of retention time, drift time, or compensation voltage for ion mobility.
14 . The system of claim 10 , wherein grouping the m/z bins is performed using a principal component analysis (PCA), a k-means clustering algorithm, or a principal component variable grouping (PCVG) algorithm.
15 . The system of claim 10 , further comprising generating a representation of the ion arrival events, the representation having an m/z dimension, a detector response dimension, and an ion count or probability dimension.
16 . The system of claim 10 , further comprising generating confidence scores for the groups, and wherein assigning the charge state is further based on at least one of the confidence scores.
17 . A method for assigning charge state in mass spectrometry, the method comprising:
receiving a detector response signal corresponding to a plurality of ion arrival events, the detector response signal comprising information related to individual ion responses generated by a detector for each ion arrival event;
based on the detector response signal, generating detector response profiles for mass-to-charge (m/z) bins of a mass spectrum generated from the ion arrival events;
grouping the m/z bins into a plurality of groups based on a similarity of the detector response profiles of the m/z bins;
identifying m/z bins that represent single-ion arrival events; and
assigning a charge state to one or more features based on the groups of m/z bins identified as having single-ion arrival events.
18 . The method of claim 17 , further comprising generating confidence scores for the groups, and wherein assigning the charge state is further based on at least one of the confidence scores.
19 . The method of claim 17 , wherein grouping the m/z bins is further based on additional separation domain data including at least one of retention time, drift time, or compensation voltage for ion mobility.
20 . The method of claim 17 , wherein identifying the m/z bins that represent single-ion arrival events is based on a frequency of observed detection events in the m/z bin.