Abstract EANA2026-257

Wet-chemical analysis enables the determination of ionic composition and key physicochemical properties of liquid samples, providing valuable insights into geological processes and the habitability of planetary environments. Ion-selective electrodes (ISEs) provide a compact and low-power approach for determining the ionic composition, pH, and redox state of extraterrestrial aqueous environments, providing essential geochemical context for the interpretation of potential biosignatures. However, reliable ISE operation requires precise and reproducible fluid handling throughout the entire measurement process. This work presents the development of an automated laboratory system that implements the complete ISE measurement workflow while providing a flexible platform for optimizing its fluidic architecture. The system combines automated fluid handling, valve control, electrode readout, and synchronized data acquisition to perform repeatable calibration sequences with minimal user intervention. To assess the influence of fluid delivery on electrochemical performance, syringe, peristaltic, and pneumatic pumping concepts are evaluated with respect to flow stability, pressure fluctuations, bubble formation, and measurement repeatability. Results demonstrate that the fluidic architecture has a significant impact on the stability and repeatability of ISE measurements. Flow-induced fluctuations and entrained air bubbles were identified as major sources of measurement variability, highlighting the importance of robust fluid handling for autonomous operation. The developed laboratory system provides a reproducible environment for evaluating and optimizing automated ISE measurements and establishes the foundation for a compact, portable electrochemical analysis platform. The presented work contributes to the development of reliable wet-chemical instrumentation for future astrobiology missions targeting ocean worlds and other aqueous planetary environments.