RESUMO
A new method, based on liquid chromatography--electrospray/tandem mass spectrometry, for the determination of abscisic acid (ABA), an essential plant hormone that regulates key metabolic pathways and responses to environmental cues, has been developed. Substantial changes in extraction procedures are also proposed. Data indicate that the organic solvents classically used as extraction buffers can be substituted by an aqueous solution, resulting in the same amounts of extracted ABA. The new method, which uses minute amounts of plant tissue, has an estimated limit of detection below 50 pmol ABA/g, and the sensitivity of the technique allows the analysis of ABA in crude plant extracts. Overall, this new rapid, sensitive and accurate procedure to determine ABA will allow analysis of multiple samples in a short time and represents a clear advantage in comparison with the conventional procedures involving many preparative steps and large amounts of plant tissue.