Headspace solid-phase microextraction for the determination of trace levels of taste and odor compounds in water samples

The use of the headspace solid-phase microextraction (SPME) technique, combined with gas chromatography-ion-trap detection mass spectrometry (GC-ITDMS), for the determination of 34 taste- and odor-causing organic compounds in water is presented. The compounds studied include aliphatic hydrocarbons, aldehydes, ketones and alcohols. The factors affecting the headspace SPME process, such as fiber type, salt addition, stirring, headspace volume and sampling time, were examined. The polydimethylsiloxane-divinylbenzene-coated fiber was found to be effective for the extraction of the compounds studied. The precision of the method was evaluated with spiked bidistilled water and river water samples. The RSDs obtained were similar for both water samples and in the range 4.3-17.1%. Using the standard addition calibration method, the problem of matrix effects observed for river water samples can be reduced. The method showed good linearity over two orders of magnitude of concentration in river water. With 40 ml of water sample, the detection limits were lower than 1 ng l(-1) for 2-methylisoborneol and geosmin, and 0.8-50 ng l(-1) for the other compounds.