In a mixture of molecular gases with compositions (CO2-N-2-H2O and CO-N-2-H2O) and total pressure close to that of the Earth's early atmospheres, a centimeter-sized plasma was created by focusing a single 85-J, 450-ps near-infrared laser pulse in a center of 15-L gas cell. Chemical consequences of the laser-produced plasma generation in such a mixture were investigated using high-performance liquid chromatography with mass-spectrometric detection (HPLC/MS). Amino acids were identified in the reaction mixture containing CO2 as well as in that one based on CO, both exposed to 10 laser shots. (C) 2004 Elsevier B.V. All rights reserved.