Mass spectrometer simulator configuration

Mass Spectrometer Simulator Configuration

License: restricted — no clear open-source license detected for the underlying tool; verify licensing before commercial use or redistribution. <!-- asb-license-banner -->

Summary

Configure a virtual mass spectrometer instance within the ViMMS framework to simulate tandem MS/MS acquisition on a chemical mixture with specified polarity, ionization mode, and detector parameters. This skill enables prototyping of fragmentation strategies before real instrument deployment.

When to use

When you have a list of chemical compounds (with m/z values, retention times, and intensities) and need to simulate their acquisition behavior under a specific ionization polarity and mass spectrometer configuration. Use this skill as the second step after generating or extracting chemicals, immediately before attaching a controller to orchestrate the fragmentation strategy.

When NOT to use

• Your chemicals are already represented as raw spectrum objects or mzML files without extracted m/z/RT/intensity metadata; use ChemicalMixtureFromMZML first.
• You need to simulate instrument-specific hardware behavior (e.g., Thermo Orbitrap resolution curves, Agilent Q-TOF drift); ViMMS provides idealized independent mass detection.
• You are replaying real acquired data without modification; use mzML replay features instead of configuring a new virtual spectrometer.

Inputs

• chemical list (list of Chemical objects with m/z, retention time, intensity, and MS levels)
• polarity setting (string: 'positive' or 'negative')
• optional: ionization mode parameters

Outputs

• configured IndependentMassSpectrometer instance
• internally tracked scan list (populated after Environment.run())

How to apply

Instantiate an IndependentMassSpectrometer class with the chemical mixture and polarity setting (positive or negative ion mode). Pass the extracted or generated chemical list (e.g., from ChemicalMixtureFromMZML or ChemicalMixtureCreator) to the constructor. The mass spectrometer will model scan-level MS1 and MS2 acquisition behavior based on the chemical properties (m/z, retention time, intensity) without requiring real instrument hardware. Configure isolation window, m/z tolerance, intensity thresholds, and retention-time tolerance as parameters to the downstream controller, not the mass spectrometer itself. The mass spectrometer acts as a virtual detector that simulates peak intensity evolution over time and fragmentation patterns according to the controller's strategy.

Related tools

• ViMMS (Core framework providing IndependentMassSpectrometer class and virtual acquisition simulation engine) — https://github.com/glasgowcompbio/vimms
• Python (Language for instantiating and configuring the mass spectrometer object)
• OpenMS (Optional post-simulation tool for peak picking and fragmentation coverage analysis on mzML output)

Examples

ms = IndependentMassSpectrometer(polarity="positive", chemicals=chemicals)

Evaluation signals

• IndependentMassSpectrometer instance is created without errors and accepts the chemical list and polarity argument.
• After Environment.run(), the scans list is non-empty and contains both MS1 and MS2 scan records with matching chemical m/z values.
• MS1 intensity profiles evolve over retention time in a manner consistent with the input chemical retention times and peak widths.
• MS2 spectra are only generated when controller triggers fragmentation based on MS1 intensity, isolation window, and m/z tolerance constraints.
• Exported mzML file contains valid scan metadata (polarity, precursor m/z, isolation window, retention time) conforming to mzML schema.

Limitations

• IndependentMassSpectrometer does not model instrument-specific mass accuracy, resolution, or detector saturation; it assumes ideal peak shapes and m/z detection.
• Fragmentation intensity distribution is determined by the attached controller strategy, not by real peptide/metabolite fragmentation chemistry.
• Chemical list must include retention times for realistic scan timing; purely m/z-based chemical lists will be assigned default or synthetic retention times.
• The simulator runs in silico and does not interact with actual Thermo Fisher IAPI or other hardware APIs; hardware integration requires separate instrumentation layers.

Evidence

• [other] Set up a virtual mass spectrometer ms = IndependentMassSpectrometer(polarity="positive", chemicals=chemicals): "Set up a virtual mass spectrometer ms = IndependentMassSpectrometer(polarity="positive", chemicals=chemicals)"
• [readme] ViMMS provides scan-level control simulation of the MS2 acquisition process in a virtual environment. You can generate new LC-MS/MS data based on empirical data or virtually replay a previous LC-MS/MS analysis using existing data: "ViMMS provides scan-level control simulation of the MS2 acquisition process in a virtual environment"
• [other] Instantiate an IndependentMassSpectrometer in positive-ion mode with the generated chemical list: "Instantiate an IndependentMassSpectrometer in positive-ion mode with the generated chemical list"
• [intro] a flexible and modular framework designed to simulate fragmentation strategies in tandem mass spectrometry-based metabolomics: "a flexible and modular framework designed to simulate fragmentation strategies in tandem mass spectrometry-based metabolomics"
• [other] Extract chemicals from the Beer1pos mzML using ChemicalMixtureFromMZML class to create a chemical list with known retention times and m/z values. Set up an IndependentMassSpectrometer with the extracted chemicals in positive polarity mode.: "Extract chemicals from the Beer1pos mzML using ChemicalMixtureFromMZML class to create a chemical list with known retention times and m/z values. Set up an IndependentMassSpectrometer with the"