Gas chromatography/isotope ratio mass spectrometry of leaf wax n‐alkalines from plants of differing carbon dioxide metabolisms

Individual n‐alkalines isolated from the leaf‐surface waxes of plants utilizings differing photosynthetic pathways were analysed using gas chromatography/isotope mass spectrometry (GC/IRMS), in order to obtain the ratios of 13 C to 12 (δ 13 ). Marked differences in the average 13 C‐depletion of the n‐alkalines relative to whole leaf tissues were observed (C 3 = −7.7‰; C 4 = −9.9‰; CAM = −11‰). Additionally, all three metabolic types exhibited considerable differences of 13 C‐depletion between n‐alkaline homologues isolated from the same plant.