Episode
Episode 51: Did Mars Destroy Its Own Biosignatures? | GC-MS, Sterols & the Search for Life
- Published
- Mar 9, 2026
- Duration seconds
- 1703
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Summary
What if Mars already had biosignatures… and destroyed them?In this episode of Concentrating on Chromatography, host David Oliva sits down with Megan Farrah from Tufts University to explore how GC-MS is being used to reconstruct potential biosignatures under simulated Martian conditions.Inside a Mars Simulation Chamber, Megan irradiates sterols and hopanes — two of NASA’s priority targets for life detection — in soil matrices containing oxychlorine salts similar to those detected by Mars missions.Her goal? Determine whether chlorinated hydrocarbons detected by rover-based pyrolysis GC-MS were:* Indigenous Martian organics* Terrestrial contamination* Or molecules altered by heat during analysisWe dive deep into:🔬 SIM mode vs. full scan when you don’t know what you’re looking for🧂 Why residual salts can destroy a GC column (and how ion chromatography prevents it)🔥 The dangers of heating organics in the presence of perchlorates🧪 Toluene/BHT extraction and preventing artificial oxidation🧼 GC-MS contamination: septa, liners, plasticizers, detergents, and why her entire bench is glass🚀 What Mars Sample Return would require from separation scientistsMegan explains why finding “organics” does not automatically mean finding life — and why Mars is far from geologically dead.We also explore how she explains Mars chemistry to fifth graders using paper chromatography… and why separation science still feels like magic.If you care about:* GC-MS method development* Column contamination control* Environmental salt matrices* Astrobiology* Or the future of life detectionThis is an episode you don’t want to miss.Topics Covered• Mars Simulation Chamber experiments• Sterols and hopanes as biosignatures• Oxidant-induced fragmentation• Derivatization with BSTFA• Ion chromatography salt cleanup…