Submersible Capillary Electrophoresis Analyzer: A Proof-of-Concept Demonstration of an In Situ Instrument for Future Mis-sions to Ocean Worlds

We report here the first fully automated capillary electrophoresis system (CE) that can be operated underwater. The system per-forms sample acquisition and analysis by coupling CE to contactless conductivity detection. Using 5 M acetic acid as the back-ground electrolyte (BGE), inorganic cations and amino acids at concentrations as low as 5.2 µM can be separated and identified. This technology could be augmented to include a variety of other detection modes. Fleets of such systems could be deployed ro-botically to generate chemical and biological gradients over regional to global scales, enabling ecosystem level studies at an un-precedented level of molecular detail. Additionally, this system serves as an early prototype for potential future underwater ex-plorers on ocean worlds of the outer solar system such as Europa or Enceladus. This work documents the first step in the devel-opment of this general-purpose technology platform.