Microfluidic Chromatography for Enhanced Amino Acid Detection at Ocean Worlds

Area of Science:

• Astrobiology
• Planetary Science
• Analytical Chemistry

Background:

• Growing interest in detecting biosignatures like amino acids on icy moons.
• Challenges posed by extreme environments: dilute biosignatures and high salinity.
• Need for sensitive detection methods for *in situ* analysis.

Purpose of the Study:

• To develop a compact, *in situ* cation exchange method for desalting amino acids.
• To improve the sensitivity of detecting biogenic signatures in extraterrestrial samples.
• To create a versatile purification device compatible with various analytical techniques.

Main Methods:

• Utilized a modular microfluidic device for cation exchange.
• Tested binding capacity with phenylalanine and model cations (Na+, Mg2+, Ca2+).
• Evaluated performance with mixtures of 17 amino acids and terrestrial ocean sample chemistry.

Main Results:

• Achieved phenylalanine recovery of 94-17% with 30-200 times conductivity reduction.
• Demonstrated effectiveness across high salt-to-amino-acid ratios (25:1 to 500:1).
• Observed amino acid recoveries ranging from 11% to 85% based on side chain chemistry and cation competition.

Conclusions:

• The novel cation exchange method effectively purifies amino acids from high-salinity samples.
• The microfluidic device offers a nondestructive approach for biosignature analysis.
• This technology can enhance the characterization of potential life on ocean worlds.