A Standard Method for Quantification of Earthy-Musty Odorants in Water, Sediments, and Algal Cultures

Abstract

The closed-loop stripping analysis (CLSA) method of Grob, in combination with gas chromatography/mass spectrometry (GC/MS), has been used in the determination of five earthy-musty-smelling compounds (including geosmin and 2-methylisoborneol). One-liter water samples are analyzed within 3 hours, with detection limits as low as 2 ng/l each. Precision and accuracy levels of 20 percent or better are obtainable with this method. This technique has been modified to include the CLSA of sediments and laboratory-grown microbiological cultures in order to investigate the sources of the odorous compounds. CLSA-GC/MS provides a valuable tool for extended surveys and regular monitoring of water supplies, and it is indispensable in the understanding and management of earthy-musty taste and odor problems.