Determination of trace amounts of off-flavor compounds in drinking water by stir bar sorptive extraction and thermal desorption GC-MS.
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).
Ochiai
N
N
Yokogawa Analytical Systems Inc., Osaka, Japan.
Sasamoto
K
K
Takino
M
M
Yamashita
S
S
Daishima
S
S
Heiden
A
A
Hoffman
A
A
D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D015203:Reproducibility of Results; D013649:Taste; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply
D014874:Water Pollutants, Chemical