title: Automated trace determination of earthy-musty odorous compounds in water samples by on-line purge-and-trap-gas chromatography-mass spectrometry.
abstract: An automated technique based on purge-and-trap coupled to gas chromatography with mass spectrometric detection has been developed and optimized for the trace determination of five of the most important water odorants; 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 2-methylisoborneol, 2,4,6-trichloroanisole and geosmin. The extraction method was absolutely solvent-free. Analytes were purged from 20 ml of water sample containing sodium chloride at room temperature by a flow of He and trapped on a Tenax sorbent. The desorption step was performed with helium and temperature programming and desorbed analytes were directly transferred to a gas chromatograph coupled to a mass spectrometer for separation and determination. The method was reproducible (RSD<8%) and linear over the calibration range (10-200 ngl(-1)). The relative recoveries of the analytes from ground water sample were calculated and were between 80 and 103% and limits of detection (LOD) below odor thresholds were achieved for most of the compounds.
authors.affiliation: Department of Chemistry, Sharif University of Technology, P.O. Box 11365-9516, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Salemi
authors.forename: Sílvia
authors.initials: S
authors.lastname: Lacorte
authors.forename: Habib
authors.initials: H
authors.lastname: Bagheri
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
mesh_terms: D000840:Anisoles / Q000032:analysis; D001331:Automation; D001892:Camphanes / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009284:Naphthols / Q000032:analysis; D009812:Odorants / Q000032:analysis*; D009862:Online Systems; D011719:Pyrazines / Q000032:analysis; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry*
chemical_list: D000840:Anisoles; D001892:Camphanes; D009284:Naphthols; D011719:Pyrazines; D014867:Water; C024267:2-isopropyl-3-methoxypyrazine; C005536:2-methylisoborneol; C110228:2,4,6-trichloroanisole; C001278:geosmin; C034376:2-isobutyl-3-methoxypyrazine