Astrobiochemistry: Detection of Amino acids and nucleotide bases

[CJSGrailKnigh]

So I'm working on a project for my fourth year class in Space Mission Design and Analysis (I'm a fourth year space systems engineering student). My project is an astrobiology mission to Titan, Saturn's sixth moon, which is only slightly smaller than Mars with a atmosphere of Nitrogen of comparable density and pressure to Earth. Part of my project is a rover that will be sampling the hydrocarbon seas on the surface.

My question is in regards to the detection of amino acids and nucleotide bases in the samples. Currently my method of detection is a ninhydrin test for the detection alpha amino acids, although I would prefer to not need liquid reagents and heavy test equipment as I have a limit of about 200kg for the entire rover and 3 other experiments, and a for the detection of the nucleotide bases I believe testing the absorbance of UV light will allow for a first order detection of nucleotide bases.

If anyone has other ideas on methodology I would greatly appreciate the input.

*In case people are curious the other experiments are soil samples with differential scanning calorimetry, radiation levels, and atmospheric pressure sensors.*

 

[Navin A S]

A possible alternative to the Ninhydrin test is Gas Chromatography-Mass Spectrometry (GC-MS) which can detect a wide range of organic compounds including amino acids. GC-MS has been used in multiple space exploration missions such as the Viking Mars mission and the Stardust mission to comet Wild 2, and a simplified version can be miniaturized for use on a rover. The advantage of GC-MS is that it does not require liquid reagents and can detect many different kinds of molecules. For detecting nucleotide bases, a modified version of Ultraviolet spectroscopy could be used. This technique has been used in other astrobiological missions to detect organic molecules such as amino acids. The UV light is absorbed by the sample and the absorbance spectrum can be used to determine the presence of various molecules. It is a relatively simple technique that can be miniaturized and requires little power.