Stable isotopic compositions of carbon monoxide from biomass burning experiments

The stable isotope composition of carbon monoxide (CO) from burning plants was measured to provide insight about isotopic compositions of CO from biom ass burning. Both C-13/C-12 and O-18/O-16 ratios of CO decreased with the t ime from ignition and those trends were not depending on the plant species. delta(13)C values of produced CO were heavier (0.6-3.6 parts per thousand V-PDB) than those of the burned plants during flaming stage, but they becam e lighter (-2.1- -6.8 parts per thousand V- PDB) during smoldering stage. B ecause CO production is enhanced in smoldering stage, average isotopic comp ositions of CO from biomass burning would be lighter than those of burned p lants. For atmospheric model calculations on CO isotopes, isotopic fraction ation of CO from biomass burning should be considered. (C) 1999 Elsevier Sc ience Ltd. All rights reserved.