title: Use of an autosampler for dynamic headspace extraction of volatile compounds from grains and effect of added water on the extraction.
abstract: An autosampler attached to a purge and trap instrument was used to aid routine analyses of grain samples for volatile compounds associated with off-odors. Trapped volatiles were transferred to a gas chromatograph/mass spectrometer instrument for separation and detection. Dynamic extraction of volatiles from approximately 18 g of whole grain at 80 degrees C was accomplished by purging helium through a sample vial with a Teflon-lined septum on each end. The autosampler automatically added internal standard to the sample before purging began, which required the addition of 1 mL of water for complete transfer of the standard to the sample. The added water enhanced extraction of 1-octen-3-ol, 1-octen-3-one, and some other compounds from soybeans but not from starchy grains such as corn and wheat. Addition of a free radical scavenger, such as citric acid, greatly diminished the recovery of 1-octen-3-ol and 1-octen-3-one from soybeans.
authors.affiliation: U.S. Grain Marketing Research Laboratory, Grain Marketing and Production Research Center, Agricultural Research Service, U.S. Department of Agriculture, 1515 College Avenue, Manhattan, Kansas 66502, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Ram
authors.forename: L M
authors.initials: LM
authors.lastname: Seitz
authors.forename: R
authors.initials: R
authors.lastname: Rengarajan
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods; D002523:Edible Grain / Q000737:chemistry*; D006801:Humans; D009812:Odorants; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry; D014908:Triticum / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry
chemical_list: D009822:Oils, Volatile; D010936:Plant Extracts; D014867:Water