Ion chromatography is the state-of-the-art technique for anion separation and analysis on Earth, but it typically requires a large, powerful pump to operate at high pressures in order to speed up analysis time. The weight and power requirements of the pump interfere with creating an ideal instrument for flight. The solution is to run the ion chromatography system at low pressure to allow the use of a smaller, lower-power pump for flight, but at the expense of longer analysis time.
Mars-relevant anion mixtures were successfully separated at low flow/pressures using a breadboard ion chromatography system that uses a pressurized vessel as a pump instead of the mechanical pumps used in commercial instruments. Comparable separation and limits of detection to the high pressure system were achieved at low pressure with analysis times of ≈2.5 to 3 h.