Purge-and-Trap Extraction Using a Solid-Phase Extraction Device for Musty Odor Compounds in Water Samples

Abstract

This study reports a new analytical method for the musty odor compounds 2-methylisoborneol and geosmin in water samples using a high-flow-rate purge-and-trap extraction with a solid-phase extraction (SPE)–type collection device, followed by analysis using gas chromatography–mass spectrometry (GC–MS). For the sample preparation, 500 mL of water sample and sodium chloride were placed in a glass vial. An SPE device packed with styrene–divinylbenzene polymer particles was attached to the vial cap, and the headspace gas was collected at a flow rate of 1 L/min for 30 min. During the gas sampling, clean air was introduced into the sample solution through a purge gas supply tube, while the musty odor compounds were purged from the water sample and extracted onto the adsorbent. The extracted compounds were eluted with 1.0 mL of dichloromethane, and the eluent was concentrated to 0.1 mL via nitrogen blowdown. The analytes were measured by GC–MS after injection of the eluent. The limit of detection for the analytes were 0.5 ng/L. The spike recoveries of the analytes from tap and river water ranged from 94 to 105%. Finally, the applicability of the method was investigated for determining the musty odor compounds 2,4,6-trichloroanisole and 2,4,6-tribromoanisole in water samples.