RAPID ANALYSIS OF GEOSMIN AND 2-METHYLISOBORNEOL IN WATER USING SOLID-PHASE MICRO EXTRACTION PROCEDURES

Geosmin (GSM) and 2-methylisoborneol (MIB) are algae metabolites with muddy/musty odors which contaminate water supplies and can be absorbed by aquatic organisms. Humans can perceive them in water and aquatic f ood products at ng/l (parts per trillion) concentrations. A rapid meth od employing solid phase micro extraction (SPME) has been developed fo r the analysis of GSM and MIB in water. Routine quantification at mu g /l concentrations can be accomplished using gas chromatography and fla me ionization detection (FID) on a 6 ml aqueous sample with a total an alysis time of less than 15 min. Concentration levels of MIB and GSM a t 10 ng/l (parts per trillion) can be detected under optimal condition s employing GC/MS in selected ion monitoring mode. Standard solutions and water samples from MIB producing algae cultures were used to compa re SPME against purge and trap (P&T) using both flame ionization and m ass spectrometric detection. Results obtained from SPME and PET were s imilar in terms of reproducibility and sensitivity. This paper reports a simple, rapid method for monitoring the algal production of MIB and GSM at the mu g/l range which can be extended to the drinking water l evels at the ng/l range of concentrations. Published by Elsevier Scien ce Ltd.