Determination of abscisic acid in Eucalyptus haemastoma leaves using gas chromatography/mass spectrometry and deuterated internal standards

Abscisic acid and 2-trans-abscisic acid each with three deuterium atoms in the C-3 methyl group, have been synthesized chemically and used as internal standards in selected ion monitoring experiments to establish the endogeneous concentrations of these compounds and their conjugates in turgid and wilted Eucalyptus haemastoma leaves. The analytical procedure used GC/CIMS(methane) to detect the methyl esters of abscisic acid, 2-trans-abscisic acid and their deuterated internal standards. A three-fold increase in the concentration of abscisic acid occurred on wilting and the amounts of 2-trans-abscisic acid and conjugates of both compounds were determined.