Molecular and carbon and hydrogen isotopic composition of n-alkanes in plant leaf waxes

Molecular composition and compound-specific carbon and hydrogen stable isotope ratios of leaf wax n-alkanes are presented for 26 plant species operating C-3, C-4 and CAM photosynthetic pathways. In contrast to delta C-13 values, delta D values are not diagnostic discriminators for C-3, C-4 and CAM plants. D and delta C-13 values of n-alkanes from C-4 plants seem to express an inverse linear relationship while Some C-3 plants showed a positive relationship. The carbon and hydrocarbon isotopic correlation is dependent on plant types as well as photosynthetic pathways. However, our data imply that the combined use of carbon and hydrogen isotopic characterization may have superior diagnostic potential for source apportionment when compared with more limited isotopic approaches. (c) 2005 Elsevier Ltd. All rights reserved.