Analysis of 2-methylisoborneol and geosmin in catfish by microwave distillation-solid phase microextraction

The semivolatile cyclic alcohols 2-methylisoborneol (MIB) and geosmin (GSM) impart muddy or musty flavors to water and food products. A rapid quantitative analytical technique has been developed whereby microwave distillation is used to remove the volatile organic compounds from a lipophilic matrix into an aqueous matrix. Solid-phase microextraction (MD-SPME) is then used to extract and concentrate the analytes, which are then desorbed in the injection port of a gas chromatograph/mass spectrometer (GC/MS) for analysis. Limits of detection are 0.01 mu g/kg and limits of quantification are 0.1 mu g/kg. MD-SPME: is comparable in precision, requires no solvents, and is faster than current methods of analysis; This methodology allows detection of MIB and GSM at concentrations below human sensory thresholds in fish tissue.