Sample Preparation for MALDI-TOF Mass Spectrometry of Model Prebiotic Reactions in Simulated Ocean World Environments

Area of Science:

• Astrobiology
• Planetary Science
• Analytical Chemistry

Background:

• The search for extraterrestrial life hinges on understanding prebiotic chemistry in ocean worlds like Europa and Enceladus.
• Simulating ocean-world conditions in the lab is crucial for experimental insights but poses analytical challenges due to high salinity.
• High salt concentrations in simulated ocean-world solutions cause ion suppression, reducing sensitivity in mass spectrometry (MS).

Purpose of the Study:

• To evaluate and compare sample preparation techniques for mass spectrometry analysis of high-salinity solutions relevant to ocean worlds.
• To identify optimal methods for matrix-assisted laser desorption/ionization - time-of-flight (MALDI-TOF) MS of simulated ocean-world environments.

Main Methods:

• Comparison of three sample preparation techniques: C4 ZipTips, C18 ZipTips, and on-plate washing.
• Analysis using matrix-assisted laser desorption/ionization - time-of-flight (MALDI-TOF) mass spectrometry (MS).
• Testing with saline solutions mimicking ocean-world chemical compositions.

Main Results:

• C18 ZipTips combined with 2,5-dihydroxybenzoic acid (DHB) matrix proved optimal for MALDI-TOF MS.
• On-plate desalting with α-cyano-4-hydroxycinnamic acid (CHCA) matrix was also effective.
• Both methods offer improved sensitivity for analyzing prebiotic molecules in saline solutions.

Conclusions:

• Developed and validated simple, low-volume sample preparation strategies for MS analysis of ocean-world simulants.
• These methods enhance the detection of prebiotically relevant systems in high-salinity extraterrestrial environments.
• Improved analytical techniques are vital for advancing the search for life beyond Earth.