Purge and Trap Extraction of Musty Odor Compounds by Thermal Desorption Tube Packed with Polydimethylsiloxane-Coated Macroporous Silica Adsorbent

This study focused on the extraction of musty odor compounds, specifically 2-methylisoborneol (2-MIB) and geosmin, from water samples using a thermal desorption (TD) tube packed with a polydimethylsiloxane-coated macroporous silica adsorbent, employing the purge and trap (PT) method. The TD tube was subsequently inserted into a portable TD system, where the extracted compounds were thermally desorbed and introduced into a gas chromatograph-mass spectrometry for analysis. During the PT extraction, the purge gas was flowed at a rate of 200 mL/min for 30 min. Owing to the hydrophobic nature of the PDMS-coated adsorbent, water vapor did not interfere with either the extraction or the desorption processes. The limits of detection and the spike recoveries in tap water samples for 2-MIB and geosmin in a 100 mL water sample were found to be 3.0 and 0.3 ng/L and 108 and 98%, respectively.