Gas Chromatographic and Mass Spectrometric Methods Applied to the Analysis of Lunar Samples from the Sea of Tranquillity

Ten different gas chromatographic and mass spectrometric methods have been applied to the characterization of organic and organogenic matter in the lunar samples from Apollo 11. Among them, flame ionization gas chromatography was used in the search for any organic extractable compounds, amino acids and pyrolytic products. Combined GC-MS provided data on the thermal evolution of gases and compounds generated by acid treatment, a new technique developed in the course of this project. In order to extend and complement the data obtained by these chromatographic methods, spark ionization mass spectrography was used to estimate the elemental abundances. Combined differential thermal analysis and high resolution mass spectrography supplied thermodynamic data on the thermal evolution of gases. Direct volatilization quadrupole mass spectrometry yielded complementary information pertinent to all the above experiments. Other methods used included stable carbon isotopic ratio mass measurements and ion microprobe mass analysis of solid species of carbon. The elements necessary for the formation of organic compounds as measured by spark ionization mass spectrography amounted to (in ppm) H = 1, C = 41, N = 20, S = 4200 and P = 270. In addition to noble gases and nitrogen the major compounds of carbon released by heating were carbon monoxide and carbon dioxide with very small amounts of methane (CO>CO2>>CH4). The concentration of total carbon was found to be surface-correlated. Amounts of the order of 200 ppm were measured. Hydrogen sulfide, CO2 and CH4 and traces of C2H2, C2H4 and C2H6 were also released from the fines by acid treatment. The δ13C isotope ratio values ranged from +2.6 to +18.5′ vs the PDB standard, values which are definitely non-terrestrial. Solid species of carbon were photographed for the first time by means of a direct imaging ion microprobe instrument. In summary, the methods employed, some of them specially designed for this study, constitute new GC-MS approaches for the search and characterization of organic and organogenic compounds evolved by heat, acid, or other treatments from igneous materials. It may be concluded that if all the above gases together with water were generated in a planetoidal body of sufficient gravitational field, such as the primitive earth, the resulting atmosphere and hydrosphere would have eventually produced organic molecules of biological significance.