Solvent jet desorption capillary photoionization-mass spectrometry

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Chemical Analysis

Background:

• Ambient mass spectrometry methods are crucial for direct sample analysis.
• Existing techniques may have limitations in sensitivity, analyte range, or spatial resolution.

Purpose of the Study:

• To introduce and characterize a new ambient mass spectrometry method: solvent jet desorption capillary photoionization (DCPI).
• To evaluate the performance of DCPI in terms of sensitivity, analyte range, and spatial resolution.

Main Methods:

• Utilizing a solvent jet generated by a coaxial nebulizer at ambient conditions.
• Directing the solvent jet onto a sample surface for analyte extraction into secondary droplets.
• Employing a heated capillary photoionization (CPI) device with 10 eV VUV photons for ionization.
• Coupling the CPI device to a mass spectrometer (MS) for high ion transfer efficiency.

Main Results:

• Achieved high sensitivity for both nonpolar and polar compounds, with limits of detection down to low femtomole (fmol) levels.
• Demonstrated capability for analyzing a wide range of molecules, from small to large, including peptides.
• Obtained good spatial resolution of 250 μm.
• Successfully applied DCPI to analyze compounds in sage leaves and chili pepper samples.

Conclusions:

• Solvent jet DCPI is a versatile and sensitive ambient mass spectrometry technique.
• The method combines atmospheric pressure photoionization and solvent assisted inlet ionization for broad analyte coverage.
• DCPI shows significant potential for direct analysis of complex biological and food samples.