Improved performance of ion trap mass spectrometer with added octopole and dodecapole fields
The geometry of commercial ion trap mass spectrometer has been intentionally distorted to improve the performance. The distortion of the geometry generates additional higher order multipole components. The non-linear resonance caused by multipole components results in rapid ejection of ions from ion trap and mass resolution and mass accuracy was improved. The multipole components can also increase the trap efficiency and improve the sensitivity and dynamic range. But excess amount of multipole components degrade the mass isolation resolution. For example, with the presence of positive octopole field in addition to quadrupole field, the resonance curve of ion trap has sharp edge on high frequency side because of the non-linear resonance, but has gentle slope on low frequency side and that degrade the mass isolation resolution when FNF waveform mass isolation was performed. It was found that by carefully choosing the electrode geometry, the resonance curve have sharp edge on both high and low frequency side and this enables higher mass isolation resolution even with highly distorted quadrupole ion trap mass spectrometer.
- Content Type:
- Paper
- Document Number:
- PO-CON1627E
- Product Type:
- Liquid Chromatograph-Mass Spectrometry, Mass Spectrometry
- Keywords:
- LCMS-IT-TOF
- Language:
- English
- File Name:
- jpo116069.pdf
- File Size:
- 3,085kb