title: In-field Volatile Analysis Employing a Hand-held Portable GC-MS: Emission Profiles Differentiate Damaged and Undamaged Yellow Starthistle Flower Heads.
abstract: BACKGROUND
  Understanding the complex chemical signalling of plants and insects is an important component of chemical ecology. Accordingly, the collection and analysis of chemical cues from plants in their natural environment is integral to elucidation of plant-insect communications. Remote plant locations and the need for a large number of replicates make in situ headspace analyses a daunting logistical challenge. A hand-held, portable GC-MS system was used to discriminate between damaged and undamaged Centaurea solstitialis (yellow starthistle) flower heads in both a potted-plant and natural setting.
  
  
  OBJECTIVE
  To determine if a portable GC-MS system was capable of distinguishing between undamaged and mechanically damaged plant treatments, and plant environments.
  
  
  METHODS
  A portable GC-MS utilising needle trap adsorbent technology was used to collect and analyse in situ headspace volatiles of varying yellow starthistle treatments. Principal component analysis (PCA) was used to distinguish treatments and identify biomarker volatiles. Analysis of variance (ANOVA) was used to determine differences between treatment volatile amounts.
  
  
  RESULTS
  The portable GC-MS system detected 31 volatiles from the four treatments. Each GC-MS run was completed in less than 3 min. PCA showed four distinct clusters representing the four treatments - damaged and undamaged potted plant, and damaged and undamaged natural plant. Damage-specific volatiles were identified.
  
  
  CONCLUSIONS
  The portable GC-MS system distinguished the treatments based on their detected volatile profiles. Additional statistical analysis identified five possible biomarker volatiles for the treatments, among them cyclosativene and copaene, which indicated damaged flower heads.
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, US Department of Agriculture, Albany, CA, USA.|Department of Environmental Toxicology, University of California, Davis, CA, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Beck
authors.affiliation: Torion Technologies Incorporated, American Fork, UT, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Porter
authors.affiliation: Poisonous Plant Research Laboratory, Agricultural Research Service, US Department of Agriculture, Logan, UT, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cook
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, US Department of Agriculture, Albany, CA, USA.
authors.forename: Wai S
authors.initials: WS
authors.lastname: Gee
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, US Department of Agriculture, Albany, CA, USA.
authors.forename: Corey M
authors.initials: CM
authors.lastname: Griffith
authors.affiliation: Torion Technologies Incorporated, American Fork, UT, USA.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Rands
authors.affiliation: Torion Technologies Incorporated, American Fork, UT, USA.
authors.forename: Tai V
authors.initials: TV
authors.lastname: Truong
authors.affiliation: European Biological Control Lab, Agricultural Research Service, US Department of Agriculture, Montpellier, France.
authors.forename: Lincoln
authors.initials: L
authors.lastname: Smith
authors.affiliation: Foodborne Toxin Detection and Prevention, Agricultural Research Service, US Department of Agriculture, Albany, CA, USA.
authors.forename: Itxaso
authors.initials: I
authors.lastname: San Román
mesh_terms: D031179:Centaurea / Q000737:chemistry*; D004777:Environment; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D056626:Inflorescence / Q000737:chemistry* / Q000254:growth & development; D010323:Passive Cutaneous Anaphylaxis; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D055549:Volatile Organic Compounds
keywords: Semiochemicals; in situ; plant volatiles