Performance evaluation of a Loeb-Eiber mass filter at 1 Torr.

Area of Science:

• Analytical Chemistry
• Physical Chemistry
• Materials Science

Background:

• The Loeb-Eiber mass filter operates effectively at high pressures (~1 Torr) due to collisional dampening.
• Miniaturization of mass filters is desirable for portable applications, requiring low power and high pressure capabilities.

Purpose of the Study:

• To construct a chip-based Loeb-Eiber mass filter using silicon-on-insulator (SOI) microfabrication.
• To verify key operational principles of the Loeb-Eiber mass filter in a miniaturized format.

Main Methods:

• Fabrication of a Loeb-Eiber mass filter using commercial SOI microfabrication techniques.
• Real-time characterization of transmitted ions using a hybrid instrument combining the Loeb-Eiber filter with a linear quadrupole mass analyzer.

Main Results:

• Successful operation and verification of ion filtering at ~1 Torr.
• Demonstrated linear relationship between ion transmission current and RF amplitude.
• Confirmed linear relationship between cutoff voltage and mass-to-charge ratio.
• Showcased superior ion filtering with square waveforms compared to sinusoidal waveforms.

Conclusions:

• The chip-based Loeb-Eiber mass filter is viable for high-pressure operation and miniaturization.
• The study validates critical aspects of Loeb-Eiber mass filter theory in a microfabricated device.
• This technology holds promise for developing compact and efficient mass spectrometry instruments.