No abstract

The musty-odor compounds (MOCs) 2-methylisoborneol (2-MIB) and geosmin in water samples were determined by a purge-and-trap method using a needle-type extraction device followed by gas chromatography-mass spectrometry. For the extraction of these compounds, a triple-layer-type extraction needle containing divinylbenzene and activated carbon particles as the particulate extraction media was introduced. Several experimental parameters, including the sample temperature during extraction, the addition of sodium chloride, and desorption conditions, were thoroughly optimized in this study. The detection limits for 2-MIB and geosmin were 1.0 and 0.5 ng L -1 , respectively. The method was successfully applied to the simultaneous determination of MOCs and other volatile organic compounds in tap-water samples.

Flavor compounds in beverages were determined by a purge-and-trap (PT) method with a needle-type extraction device in gas chromatography-mass spectrometry. Optimum extraction medium was quantitatively evaluated for extraction/desorption of target analytes. A graphite carbon adsorbent of Carbopack X showed excellent extraction and desorption efficiencies for all the investigated flavor compounds in this PT method. On the basis of a systematic optimization of the several experimental conditions, a simple and quantitative analytical method was developed for a wide range of flavors including esters, alcohols, and aromatic compounds. The limit of quantification of the analytes were in the range from 0.5 to 10 μg/L. The proposed PT method was successfully applied to the determination of flavor compounds in commercially available beverages and fruit juices.