Ion soft landing using a rectilinear ion trap mass spectrometer.

Area of Science:

• Mass spectrometry
• Surface science
• Analytical chemistry

Background:

• Controlled deposition of mass-selected ions is crucial for surface modification and molecular analysis.
• Existing methods often suffer from ion loss and limited mass selection capabilities.

Purpose of the Study:

• To develop and characterize a new ion soft landing instrument for precise deposition of polyatomic ions.
• To evaluate the performance of a novel rectilinear ion trap (RIT) mass analyzer within the instrument.

Main Methods:

• Utilizing an electrospray ionization source coupled with an electrodynamic ion funnel for reduced ion loss.
• Employing a 90-degree bent square quadrupole and a rectilinear ion trap (RIT) for mass analysis and filtering.
• Implementing three mass analysis modes: instability scan, continuous rf/dc filtering with RIT, and continuous rf/dc filtering with the quadrupole.

Main Results:

• The RIT achieved a mass resolution of approximately 550 in trapping mode.
• Intact deposition of [Val (5)]-Angiotensin I was confirmed using Desorption Electrospray Ionization (DESI).
• Soft landing yields ranged from 0.2 to 0.4%, with mass-selected currents up to 500 pA.

Conclusions:

• The new instrument effectively performs controlled soft landing of mass-selected ions.
• The novel continuous mass selection methods enhance soft landing yields while enabling full mass spectra acquisition.
• This technology offers a promising platform for surface functionalization and molecular deposition studies.