An open tubular ion chromatograph

Area of Science:

• Analytical Chemistry
• Separation Science
• Astrochemistry

Background:

• Traditional ion chromatography (IC) faces limitations in speed and portability for field analysis.
• Analyzing soil samples for compounds like perchlorate is crucial for planetary exploration, particularly for Mars missions.

Purpose of the Study:

• To develop and characterize an Open Tubular Ion Chromatograph (OTIC) for high-performance separations.
• To assess the suitability of OTIC for extraterrestrial applications, focusing on Martian soil analysis.

Main Methods:

• Utilized anion exchange latex-coated silica and poly(methyl methacrylate) tubes for column fabrication.
• Implemented automated time/pressure-based hydrodynamic injection for pL-nL scale sample introduction.
• Employed an optimized admittance detector for non-suppressed detection.

Main Results:

• Achieved routine generation of over 50,000 plates (up to 150,000 plates/m) for fast separations.
• Demonstrated limit of detections (LODs) from submicromolar to double-digit micromolar for various analytes.
• Showcased adaptability through various eluents, organic modifiers, and pH adjustments for tailored separations.

Conclusions:

• OTIC provides fast, high-efficiency separations comparable or superior to conventional IC.
• The system's durability (surviving drying/freezing), small footprint, low power, and simplicity make it a strong candidate for space missions.
• OTIC is well-suited for confirming the presence of perchlorates in Martian soil and other extraterrestrial analyses.