Mass error correction due to thermal drift in a time of flight mass spectrometer
AssigneeThermo Fisher Scientific (Bremen) GmbH
InventorsChristian Albrecht Hock, Hamish Stewart
Life of this patent
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Abstract
A method of calibrating a TOF-MS mass spectrum, to account for temperature changes, is disclosed. Ions are introduced into a Fourier Transform Mass Spectrometer and their mass to charge ratios are determined. Ions, including calibrant ions, are also introduced into a time of flight mass spectrometer and the mass to charge ratios of the calibrant ions at least are also determined. Specific peaks representative of calibrant ions are selected and matched between the TOF MS and FTMS spectra. The relative position of matched peaks in each spectrum is then used to determine a temperature correction factor for the TOF MS data, based upon the relative independence of the FTMS spectrum with respect to temperature.
Claims21
A method of calibrating a TOF-MS mass spectrum, to account for temperature changes, comprising:
- (a) introducing ions into a Fourier Transform Mass Spectrometer (FTMS);
- (b) obtaining data representative of the mass to charge ratios of at least some calibrant ions of the ions introduced into the FTMS
- (c) introducing ions into a time of flight mass spectrometer (TOF MS), the ions introduced into the TOF MS including ions from the calibrant ion species;
- (d) obtaining data representative of the mass to charge ratio of at least the ions of the calibrant ion species introduced into the TOF MS;
- (e) choosing one or more peaks in the data obtained from a first of the FTMS and the TOF MS, representative of one or more calibrant ion species;
- (f) matching the or each chosen peak in the data obtained from the first of the FTMS and the TOF MS, with a corresponding one or more peaks in the data obtained from the second of the FTMS and the TOF MS and representative of the or each chosen calibrant ion species;
- (g) determining a temperature correction factor for the TOF MS data, based upon a relative position of the TOF MS and FTMS calibrant ion species peaks;
- and
- (h) applying the said temperature correction factor to data obtained by the TOF MS in order to correct the said TOF MS data for changes in temperature of the TOF MS.
A system for calibrating a TOF-MS mass spectrum, to account for temperature changes, comprising:
- (i) an ion source, arranged to generate ions;
- (j) a Fourier Transform Mass Spectrometer (FTMS) for analysing ions introduced into it, and generating data representative of the mass to charge ratios of those ions,
- (k) a Time of Flight Mass spectrometer, (TOF MS) for analysing ions introduced into it and generating data representative of the mass to charge ratios of those ions, and
- (l) a system controller, arranged to
- i. choose one or more peaks in a first of the FTMS and the TOF MS data, representative of one or more calibrant ion species introduced to the first of the FTMS and the TOF MS respectively;
- ii. match the or each chosen peak in the data obtained from the first of the FTMS and the TOF MS, with a corresponding one or more peaks in the data obtained from a second of the FTMS and the TOF MS and representative of the or each chosen calibrant ion species;
- iii. determine a temperature correction factor for the TOF MS data based upon a relative position of the TOF MS and FTMS calibrant ion species peaks;
- and
- iv. apply the said temperature correction factor to data obtained by the TOF MS in order to correct the said TOF MS data for changes in temperature of the TOF MS.
Dependencies are inferred from the claim text.