In Situ Analytical Chemistry Laboratory for the Exobiology Extant Life Surveyor

In this paper, we report a fully automated, end-to-end (sample-in/data-out) capillary electrophoresis system. The system's dimensions conform to the cylindrical shape and power/data requirements of the science payload compartment of the Exobiology Extant Life Surveyor (EELS), a snake-like robot capable of autonomously navigating challenging terrain on Earth or other worlds. The capillary electrophoresis system is equipped with three contactless conductivity detectors: two dedicated to analyte detection and one for characterizing bulk sample flow. The system enables simultaneous detection of cations and anions, including K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl⁻, and SO₄²⁻, at sub-micromolar concentrations. For the first time, we deployed and demonstrated autonomous capillary electrophoresis operation on a glacier, with the system tested in three environments: on-ice, partially submerged in an active stream, and fully submerged in a glacial pool.