Ruan ED, Aalhus J and Juarez M
The semi-volatile cyclic alcohols 2-methylisoborneol (2-MIB) and geosmin (GSM) impart muddy or musty flavors to water and fish products. A rapid quantitative analytical technique has been developed based on stir bar sorptive extraction (SBSE), coupled with thermal desorption and gas chromatography-mass spectrometry (TD-GCMS). SBSE is used to extract and concentrate the off-flavor compounds of GSM and 2-MIB in coating material polydimethylsiloxane (PDMS). The analytes are thermally released from SBSE and analyzed by GC-MS. Limits of detection (LOD) and limits of quantification (LOQ) of GSM and 2-MIB are 0.3 ng/L and 1 ng/L, based on the main fragment ions of m/z 112 and m/z 95, respectively. This methodology allows quantitative analysis of 2-MIB and GSM in both water and fish tissue successfully.