Immunoaffinity chromatography of abscisic acid combined with electrospray liquid chromatography-mass spectrometry

Polyclonal antibodies with high specificity for C1-immobilised (+)-cis,trans-abscisic acid (ABA) were raised, characterised by enzyme-linked immunosorbent assay (ELISA) and used for preparation of an inummoaffinity chromatography (IAQ gel. The detection limit of the ELISA was approximately 4.6 x 10(-10) mol/L. Sensitive electrospray liquid chromatography-mass; spectrometry (LC-ESI-MS) methods, were also developed with detection limits below 0.1 x 10(-12) mol. The IAC allowed quick, single-step processing of samples prior to the analyses. The LC-ESI-MS and LC-ELISA techniques were used for comparative estimation of endogenous ABA levels in immumoaffinity purified extracts of normal and water-stressed Nicotiana tabacum L. leaves. The analytical approaches were validated using deuterium- and tritium-labelled internal standards, respectively. The LAC method was found to be highly effective, sensitive and convenient for isolating the target analyte from plant material. (c) 2006 Elsevier B.V. All rights reserved.