Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet

Area of Science:

• Analytical Chemistry
• Mass Spectrometry

Background:

• Traditional mass spectrometry techniques face challenges in analyzing complex biological samples.
• Developing novel ionization methods is crucial for enhanced sensitivity and sample compatibility.

Purpose of the Study:

• To report the first implementation of laserspray ionization vacuum (LSIV) for mass spectrometry.
• To demonstrate LSIV's capability for direct analysis of biological tissues and labile compounds.

Main Methods:

• Conversion of electrospray ionization sources to LSIV by incorporating a custom cone and glass slide for sample deposition.
• Utilizing a laser in transmission geometry for sample ablation from the vacuum side of the glass slide.
• Optimizing inlet temperature for efficient ionization of both small and high-mass analytes.

Main Results:

• Successful operation of LSIV directly from atmospheric pressure.
• Detection of labile compounds (gangliosides, cardiolipins) as intact doubly deprotonated ions from mouse brain tissue.
• Demonstration that multiple charging improves ion mobility spectrometry separation for complex samples.

Conclusions:

• LSIV is a viable and effective technique for mass spectrometry analysis.
• The method allows for direct tissue analysis and sensitive detection of challenging analytes.
• LSIV offers advantages in terms of inlet temperature requirements and ion separation for complex mixtures.