Abscisic acid studied by fluorescent techniques.

Crude analytical abscisic acid (ABA) exhibited fluorescence (lambdaex 340, lambdaem 425 nm). The results demonstrated a relationship between fluorescence response and ABA concentration, in the range of 0.04-0.38 microgram/ml. Chromatographic purification increased the emission signal, and oxidation induced by adding a sulphuric acid: ethanol (1:1) mixture also increased and displaced it (lambdaex 450, lambdaem 495 nm). Using these properties, a fluorimetric method for identification and evaluation of ABA, had been developed, and used for inhibitor recognition in P. pinea seed coats.