On-Demand Mass Spectrometry Analysis by Miniature Mass Spectrometer

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Biochemistry

Background:

• Electrospray ionization (ESI) is crucial for biomolecule analysis via mass spectrometry (MS).
• Conventional ESI methods face challenges with control and potential side reactions due to high applied voltages.
• Existing techniques can be energy-intensive and consume significant sample volumes.

Purpose of the Study:

• To develop a novel on-demand mass spectrometry (MS) analysis method.
• To improve control and reduce side reactions in electrospray ionization (ESI).
• To enable sensitive analysis with reduced sample consumption and lower voltages.

Main Methods:

• Development of a miniature mass spectrometry (MS) system utilizing discontinuous ion injection-induced electrospray ionization (ESI).
• Implementation of a discontinuous atmospheric pressure interface for controlled ionization.
• Utilized low voltages (<300 V) for efficient ion generation.

Main Results:

• Achieved highly efficient ionization under low voltages (<300 V).
• On-demand ESI demonstrated comparable sensitivity to conventional nanoESI for various compounds.
• Observed softer ionization for proteins (myoglobin, cytochrome C) compared to standard ESI/nanoESI.
• Significantly reduced sample consumption due to on-demand ionization, enabling single-cell analysis.

Conclusions:

• The novel on-demand ESI method provides a controlled and efficient approach for MS analysis.
• This technique offers advantages in sensitivity, ionization softness, and sample conservation.
• The method is suitable for sensitive analyses, including single-cell applications, with reduced sample requirements.