Simultaneous determination of plant endogenous hormones in green mustard by liquid chromatography – Tandem mass spectrometry

Abstract

This study described a method for simultaneous determination of 14 kinds of plant endogenous hormones in Brassica Juncea (L) Czern, including indole-3-acetic acid, indole-3-butyric acid, indole-3-carboxylic acid, 3-indolepropionic acid, gibberellin A 3 , gibberellin A 4 , gibberellin A 7 , N6-benzyladenine, N6-isopentenyladenine, isopentenyladenosine, trans-zeatin, kinetin, dihydrozeatin riboside and trans-zeatin riboside. Vegetable tissues were extracted in order with 2-propanol/water/concentrated HCl (2:1:0.002, V/V ) and dichloromethane, respectively. The method showed good linearity for all 14 plant endogenous hormones, with regression coefficients ( R 2 ) > 0.9961. The limits of detection ranged from 0.2 to 32.6 ng/g, the overall average of recoveries of plant endogenous hormones ranged from 81.71% to 105.74%, and the relative standard deviation was less than 20%. The proposed method is fast, simple, sensitive, accurate, and efficient for the analysis of plant endogenous hormones in green mustards, which could be the basis to develop methods for determination of plant growth regulators in other vegetables as agricultural products. Brassica Juncea (L.) Czern samples were ground into powder using a mortar and pestle, then approximately 300 mg of each sample were added with 3 mL of 2-propanol-water-concentrated HCl (2:1:0.002, v/v) solution and 6 mL of dichloromethane, respectively. Two phases were formed by the centrifugation. The supernatant together with supernatant in the previous step, was inject directly into MS detector. Approximately 3 mL of the lower layer was concentrated using a nitrogen evaporator, and then redissolved in 1 mL of MeOH. After vortexing and centrifugation, the supernatant was filtered through 0.22-µm PTFE filter, and then analyzed by LC-ESI-MS/MS