Rapid Determination of Salicylic Acid in Plant Materials by Gas Chromatography–Mass Spectrometry

Summary Salicylic acid (SA) is a signaling compound in plants such as tobacco, cucumber, and tomato which can induce systemic acquired resistance. In the work discussed in this paper a simple, rapid, and sensitive method was developed for determination of salicylic acid in plant tissues by gas chromatography–mass spectrometry (GC–MS). SA from tomato leaves extracted with 9:1 (v/v) methanol–chloroform was derivatized by use of bis(trimethylsilyl)trifluoroacetamide (BSTFA) under the optimum reaction conditions (120 °C, 60 min). Quantitative analysis by GC–MS was performed in selected ion monitoring (SIM) mode using an internal standard. Procedures for sample preparation and reaction conditions were optimized. Analysis was completed within 2 h. A sensitivity of 10 ng g^–1 fresh weight and a relative standard deviation less than 5.0% for SA in tomato leaves were achieved. The method could be used for investigation of SA in plant tissues to monitor fast responses of plant defense.