Back to results
US 12,755,953 B2Granted
Mass spectral encoding
AssigneeMicromass UK Limited
InventorsMartin Raymond Green, Keith George Richardson
Life of this patent
Estimating the term…
Abstract
A method of mass spectrometry is disclosed in which one or more AC excitation voltage waveforms are applied to electrodes of an ion guide to radially excite and thereby attenuate ions having mass to charge ratios within respective mass to charge ratio windows. The AC excitation voltage waveforms are varied with time such that ions having different mass to charge ratios are attenuated with different attenuation time profiles. Plural AC excitation voltage waveforms may be varied with time to provide unique mass to charge ratio encoding.
Claims18
A method of mass spectrometry comprising:
- applying a first AC voltage waveform to electrodes of an ion guide so as to radially confine ions within the ion guide;
- simultaneously applying two or more AC excitation voltage waveforms to electrodes of the ion guide, wherein each of the two or more AC excitation voltage waveforms is configured to radially excite and thereby attenuate ions having a mass to charge ratio within a respective mass to charge ratio window as those ions pass through the ion guide;
- varying the two or more AC excitation voltage waveforms with time as the ions pass through the ion guide such that ions of each mass to charge ratio within a mass to charge ratio range are encoded with a unique attenuation time profile;
- and
- detecting an encoded attenuation time profile in a precursor ion or fragment ion signal;
- wherein said varying the two or more AC excitation voltage waveforms with time comprises varying both the frequency and amplitude of at least one of the two or more AC excitation waveforms with time;
- and
- wherein said varying both the frequency and amplitude of at least one of the two or more AC excitation waveforms with time comprises varying the at least one AC excitation voltage waveform substantially according to an expression, wherein the expression includes:
- a term configured to cause the respective mass to charge ratio window to scan continuously or discontinuously across a mass to charge ratio range according to an approximately linear relationship between mass to charge ratio and time;
- and
- a term configured to cause a width of the respective mass to charge ratio window to remain approximately constant as the respective mass to charge ratio window scans continuously or discontinuously across the mass to charge ratio range.
8 more elements
A mass spectrometer comprising:
- an ion guide;
- at least one voltage supply configured to apply a first AC voltage waveform to electrodes of the ion guide so as to radially confine ions within the ion guide, and to simultaneously apply two or more AC excitation voltage waveforms to electrodes of the ion guide, wherein each of the two or more AC excitation voltage waveforms is configured to radially excite and thereby attenuate ions having a mass to charge ratio within a respective mass to charge ratio window as those ions pass through the ion guide;
- and
- a control circuit configured to:
- vary the two or more AC excitation voltage waveforms with time as ions pass through the ion guide such that ions of each mass to charge ratio within a mass to charge ratio range are encoded with a unique attenuation time profile;
- and
- detect an encoded attenuation time profile in a precursor ion or fragment ion signal;
- wherein the control circuit is configured to vary the two or more AC excitation voltage waveforms with time by varying both the frequency and amplitude of at least one of the two or more AC excitation waveforms with time;
- and
- wherein said varying both the frequency and amplitude of at least one of the two or more AC excitation waveforms with time comprises varying the at least one AC excitation voltage waveform substantially according to an expression, wherein the expression includes:
- a term configured to cause the respective mass to charge ratio window to scan continuously or discontinuously across a mass to charge ratio range according to an approximately linear relationship between mass to charge ratio and time;
- and
- a term configured to cause a width of the respective mass to charge ratio window to remain approximately constant as the respective mass to charge ratio window scans continuously or discontinuously across the mass to charge ratio range.
10 more elements
A mass spectrometer comprising:
- an ion guide;
- at least one voltage supply configured to apply a first AC voltage waveform to electrodes of the ion guide so as to radially confine ions within the ion guide, and to apply one or more AC excitation voltage waveforms to electrodes of the ion guide, wherein each of the one or more AC excitation voltage waveforms is configured to radially excite and thereby attenuate ions having a mass to charge ratio within a respective mass to charge ratio window as those ions pass through the ion guide;
- and
- a control circuit configured to vary the one or more AC excitation voltage waveforms with time as ions pass through the ion guide such that ions having different mass to charge ratios are attenuated with different attenuation time profiles;
- wherein the control circuit is configured to vary the one or more AC excitation voltage waveforms with time by varying both the frequency and amplitude of at least one of the one or more AC excitation waveforms with time;
- and
- wherein said varying both the frequency and amplitude of at least one of the one or more AC excitation waveforms with time comprises varying the at least one AC excitation voltage waveform substantially according to an expression, wherein the expression includes:
- a term configured to cause the respective mass to charge ratio window to scan continuously or discontinuously across a mass to charge ratio range according to an approximately linear relationship between mass to charge ratio and time;
- and
- a term configured to cause a width of the respective mass to charge ratio window to remain approximately constant as the respective mass to charge ratio window scans continuously or discontinuously across the mass to charge ratio range.
7 more elements
Dependencies are inferred from the claim text.