In the 1950s, Louis Miller conducted a number of experiments that tried to model the origin of organic compounds in a prebiotic world. Among these was the Miller-Urey experiment, in which a vessel containing water, methane, ammonia and hydrogen was heated and subjected to electrical discharge (simulating lightning). Diagram of the experiment (Wikipedia). At the time, Miller reported that a number of amino acids were formed.
This brief article describes the reanalysis of stored vials containing the outcome of one of these experiments, using material found at the University of Chicago after Miller's death. Apparently Miller had identified five amino acids and a number of unidentified compounds in some of the experiments.
Simulating prebiotic environments isn't a field I know a great deal about: apparently opinion has swung away from then belief that the early atmosphere would have been quite so reducing. Nonetheless, the authors outline how Miller's experimental design could still be relevant to particular scenarios of primitive atmosphere.
The figure above (click for a big version - may require personal or institutional subscription to Science) shows in B the apparatus used by Miller, and in C the compounds detected (values are molar ratios relative to glycine) - newly identified compounds are underlined. A shows volcanic activity couled with lightning!
After Miller's death, several boxes containing sealed vials apparently containing dried material resulting from these experiments were discovered, and the authors selected 11 vials for analysis of their contents. The vial contents were resuspended in water and analysed using modern instruments (HPLC and LC-ToF) that allowed the detection of compounds at sub-picomolar concentrations.
What's interesting is that 22 amino acids were detected (plus a few more odds and sods) - a greater variety that originally reported by Miller.
These old "origin of life" type experiments were always interesting as they indicated that organic compounds could be formed - this report interesting as a kind of "forensic data archaeology" - perhaps it's a pointer that data or experimental material is worth preserving for the future!
A. P. Johnson, H. J. Cleaves, J. P. Dworkin, D. P. Glavin, A. Lazcano, J. L. Bada (2008). The Miller Volcanic Spark Discharge Experiment Science, 322 (5900), 404-404 DOI: 10.1126/science.1161527