Miniaturization of a planar-electrode linear ion trap mass spectrometer

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Instrumentation Engineering

Background:

• Describes the miniaturization of a linear-type ion trap mass spectrometer.
• Highlights potential applications in portable chemical analysis.
• Demonstrates advantages of lithographically patterned electrodes for ion trap fabrication.

Purpose of the Study:

• To demonstrate the viability and flexibility of patterned electrode approach for ion trap miniaturization.
• To identify potential obstacles in miniaturized ion trap fabrication.
• To explore reduction of ion trap volume without physical electrode modification.

Main Methods:

• Utilized photolithography to pattern metal electrodes on planar ceramic substrates.
• Reduced the spacing of electrodes (y0) from 2.19 mm to 0.95 mm.
• Employed a capacitive voltage divider with adjusted capacitor values to maintain electric field integrity.

Main Results:

• Achieved better than unit mass resolution for toluene molecular and fragment ions.
• Observed reduced signal due to smaller trapping capacity, but retained mass resolution.
• Demonstrated instrument performance using electron ionization mass spectra of toluene and dichloromethane.

Conclusions:

• Lithographically patterned substrates offer a viable method for fabricating miniaturized ion traps.
• Significant reduction in ion trap volume is possible without altering electrode geometry.
• Further miniaturization of ion traps using patterned ceramic plates shows promise.