Towards a radiation-tolerant contactless conductivity detector for use with capillary electrophoresis systems in spaceflight applications

Abstract The simplicity, versatility, and ease of miniaturization of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D) has led to its application for the analysis of a wide range of inorganic and organic species. While C4D detectors have relatively straightforward electronics, no designs specifically focused on spaceflight applications have been developed. The challenge lies in the limited set of components tolerant to high radiation levels and large temperature ranges when designing electronics for planetary science missions. In this work we present a C4D prototype designed for high radiation environments over the range of 50–300 krad total ionizing dose (TID). The proposed design, including selection of components, compatibility with radiation levels and the main differences compared to an open source version of the detector (OpenC4D) are discussed in detail. This prototype was also designed to allow monitoring of up to three capillaries for measurement redundancy. The Rad Hard C4D was assembled using COTS equivalents of the radiation-hardened counterparts, and its performance was evaluated by comparison to a commercial C4D device. Additionally, the reagents used for an astrobiology focused CE-C4D method developed previously were investigated for long-term storage and compatibility with high radiation levels. No loss in performance was observed for reagents exposed to 300 krad TID and stored for 2 years at room temperature.