Insights into stress degradation behavior of gibberellic acid by UHPLC Q-Exactive Orbitrap mass spectrometry.

Abstract Gibberellic acid (GA3) is widely applied in agriculture and food worldwide. Profiling the degradation products and their formation pattern under stress are helpful for deeply understanding GA3 regulating plant physiology and GA3 safety in agricultural crops. This study firstly investigated the degradation behavior of GA3. Different stress factors such as light, pH and temperatures were investigated through photolysis and hydrolysis experiments. Five degradation products were identified using ultra high-performance liquid chromatography Q-Exactive Orbitrap mass spectrometry (UHPLC Q-Exactive Orbitrap MS). Three degradation products were produced under ultraviolet photolysis conditions. Two isomers (iso-GA3 and gibberellenic acid) were formed under alkaline conditions. In order to characterize each degradation product, complete mass fragmentation pathways of all analytes were initially established. These results could provide a practical reference for the safety of agricultural products and the guidance for scientific application of GA3 and proposed storage conditions of GA3.