ABSTRACT
An automated on-line solid phase extraction-liquid chromatography-tandem mass spectrometry ( on-line SPE-LC-MS/MS ) method for the simultaneous quantification of six endogenous phytohormones including abscisic acid ( ABA ) , indole-3-acetic acid ( IAA ) , salicylic acid ( SA ) , jasmonic acid ( JA ) , indole-3-propionic acid ( IPA) and indole-3-butyric acid ( IBA) in rice tissues was described. Plant samples were extracted with methanol and on-line SPE procedure was performed with C18 SPE cartridges. Analytes were eluted to C18 analytical column with mobile phase and further analyzed by LC-MS/MS. The performance of the method was fully validated. Linearity showed good correlation (R2≥0. 99). Limits of detections (S/N=3) were in the range of 0. 1-0. 8 μg/kg. Recoveries varied between 71. 2% and 126%. The method was rapid and sensitive to determine multiple phytohormones in rice young panicles and the results were cross-validated with the off-line SPE-LC-MS/MS phytohormone analytical method. Finally, the method was applied to monitor the changes of ABA, IAA, SA and JA in wounded rice leaves. The trends were in accord with plant physiological processes.