Desorption electrospray ionization in a small pressure-tight enclosure

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Surface Analysis

Background:

• Desorption electrospray ionization (DESI) is a powerful ambient ionization technique for mass spectrometry.
• Traditional DESI setups can be complex to implement and may expose analysts to samples.
• There is a need for more robust, safer, and user-friendly DESI interfaces.

Purpose of the Study:

• To develop and evaluate a novel, enclosed DESI interface.
• To assess the safety, robustness, and ease of implementation of the new DESI system.
• To compare the performance of the enclosed DESI source with conventional open DESI systems.

Main Methods:

• A new DESI interface was designed featuring a small, pressure-tight enclosure.
• Fixed spatial relationships were established between the sprayer, surface, and sampling capillary.
• Performance was evaluated using various proteins, peptides, and small molecules, comparing enclosed and open DESI configurations.

Main Results:

• The enclosed DESI interface demonstrated improved safety and ease of use without signal loss.
• Performance was largely independent of geometrical configurations, simplifying implementation.
• Comparable results were achieved for diverse analytes, including direct analysis of 96-well plates.

Conclusions:

• The novel enclosed DESI interface offers a more robust, safer, and user-friendly alternative to conventional DESI.
• The design facilitates direct analysis of samples in formats like 96-well plates.
• This advancement simplifies DESI implementation and broadens its applicability in analytical chemistry.