N. Ochiai et al., Determination of trace amounts of off-flavor compounds in drinking water by stir bar sorptive extraction and thermal desorption GC-MS, ANALYST, 126(10), 2001, pp. 1652-1657
A method for the determination of trace amounts of off-flavor compounds inc
luding 2-triethylisoborneol, geosmin and 2,4,6-trichloroanisole in drinking
water was developed using the stir bar sorptive extraction technique follo
wed 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 extrac
ted for 60-240 min at room temperature (25 degreesC) using stir bars with a
length of 10 mm and coated with a 500 mum layer of polydimethylsiloxane. T
he extract was analyzed by thermal desorption-GC-MS in the selected ion mon
itoring 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 th
e correlation coefficients were greater than 0.9987. The detection limits r
anged 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 successful
ly applied to low-level samples (raw water and tap water).