title: Simultaneous quantification of jasmonic acid and salicylic acid in plants by vapor-phase extraction and gas chromatography-chemical ionization-mass spectrometry.
abstract: Jasmonic acid and salicylic acid represent important signaling compounds in plant defensive responses against other organisms. Here, we present a new method for the easy, sensitive, and reproducible quantification of both compounds by vapor-phase extraction and gas chromatography-positive ion chemical ionization-mass spectrometry. The method is based on a one-step extraction, phase partitioning, methylation with HCl/methanol, and collection of methylated and, thus, volatilized compounds on Super Q filters, thereby omitting further purification steps. Eluted samples are analyzed and quantified by GC/MS with chemical ionization. Standard curves were linear over a range of 5-1000 ng for jasmonic acid and salicylic acid. The correlation coefficients were greater than 0.999 and the recovery rates estimated between 70 and 90% for salicylic acid and 90 and 100% for jasmonic acid. The limit of detection was about 500 fg by using single ion detection mode. Both, cis- and trans-isomers for jasmonic acid can be detected. A comparison with established methods indicates the new method to be highly efficient, allowing reliable quantification of both compounds from small amounts of plant material (5-400mg fresh weight).
authors.affiliation: Center for Medical, Agricultural and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, 1700 SW 23rd Drive, Gainesville, FL 32608, USA.
authors.forename: Juergen
authors.initials: J
authors.lastname: Engelberth
authors.forename: Eric A
authors.initials: EA
authors.lastname: Schmelz
authors.forename: Hans T
authors.initials: HT
authors.lastname: Alborn
authors.forename: Yasmin J
authors.initials: YJ
authors.lastname: Cardoza
authors.forename: Juan
authors.initials: J
authors.lastname: Huang
authors.forename: James H
authors.initials: JH
authors.lastname: Tumlinson
mesh_terms: D000408:Alamethicin / Q000494:pharmacology; D000818:Animals; D010367:Arachis / Q000737:chemistry / Q000469:parasitology; D003517:Cyclopentanes / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D005740:Gases / Q000737:chemistry; D054883:Oxylipins; D010936:Plant Extracts / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D020156:Salicylic Acid / Q000032:analysis*; D012680:Sensitivity and Specificity; D018411:Spodoptera / Q000502:physiology; D014026:Nicotiana / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
chemical_list: D003517:Cyclopentanes; D005740:Gases; D054883:Oxylipins; D010936:Plant Extracts; D000408:Alamethicin; C011006:jasmonic acid; D020156:Salicylic Acid