Quantitation of indoleacetic Acid conjugates in bean seeds by direct tissue hydrolysis

Gas chromatography-selected ion monitoring-mass spectral analysis using [(13)C(6)]indole-3-acetic acid (IAA) as an internal standard provides an effective means for quantitation of IAA liberated during direct strong basic hydrolysis of bean (Phaseolus vulgaris L.) seed powder, provided that extra precautions are undertaken to exclude oxygen from the reaction vial. Direct seed powder hydrolysis revealed that the major portion of amide IAA conjugates in bean seeds are not extractable by aqueous acetone, the solvent used commonly for IAA conjugate extraction from seeds and other plant tissues. Strong basic hydrolysis of plant tissue can be used to provide new information on IAA content.