MICROWAVE DISTILLATION-SOLID PHASE ADSORBENT TRAPPING DEVICE FOR THE DETERMINATION OF OFF-FLAVORS, GEOSMIN AND METHYLISOBORNEOL, IN CATFISH TISSUE BELOW THEIR REJECTION LEVELS

摘要

Described is a rapid microwave-mediated steam distillation device for determining two predominant off-flavor compounds, geosmin and methylisoborneol, in catfish tissue. A microwave on-time of 10 min is needed to efficiently remove these off-flavor compounds from the sample matrix and trap them on a solid phase adsorbent, A minimal amount of organic solvent is used to elute the trapped compounds. The extract is then analyzed by gas chromatography with ion trap detection in the selective ion storage mode. Detection limits in the sub-parts-per-billion range are obtained with this method.