title: Determination of trace amounts of off-flavor compounds in drinking water by stir bar sorptive extraction and thermal desorption GC-MS.
abstract: A method for the determination of trace amounts of off-flavor compounds including 2-methylisoborneol, geosmin and 2,4,6-trichloroanisole in drinking water was developed using the stir bar sorptive extraction technique followed by thermal desorption-GC-MS analysis. The extraction conditions such as extraction mode, salt addition, extraction temperature, sample volume and extraction time were examined. Water samples (20, 40 and 60 ml) were extracted for 60-240 min at room temperature (25 degrees C) using stir bars with a length of 10 mm and coated with a 500 microm layer of polydimethylsiloxane. The extract was analyzed by thermal desorption-GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range from 0.1 or 0.2 or 0.5 to 100 ng l(-1) for all the target analytes, and the correlation coefficients were greater than 0.9987. The detection limits ranged from 0.022 to 0.16 ng l(-1). The recoveries (89-109%) and precision (RSD: 0.80-3.7%) of the method were examined by analyzing raw water and tap water samples fortified at the 1 ng l(-1) level. The method was successfully applied to low-level samples (raw water and tap water).
authors.affiliation: Yokogawa Analytical Systems Inc., Osaka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ochiai
authors.forename: K
authors.initials: K
authors.lastname: Sasamoto
authors.forename: M
authors.initials: M
authors.lastname: Takino
authors.forename: S
authors.initials: S
authors.lastname: Yamashita
authors.forename: S
authors.initials: S
authors.lastname: Daishima
authors.forename: A
authors.initials: A
authors.lastname: Heiden
authors.forename: A
authors.initials: A
authors.lastname: Hoffman
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D015203:Reproducibility of Results; D013649:Taste; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
chemical_list: D014874:Water Pollutants, Chemical