Abstract:To develop a rapid detection method for typical off-flavor；in aquatic organisms，this study used 2-isobutyl-3-methoxypyrazine（IBMP）as the internal test target and developed the detection methods of geosmin（GSM）and 2-methyli-soborneol（2-MIB）in fish tissues based on the dispersed solid phase extraction technology and gas chromatography-tandem mass spectrometry.The method used acetonitrile as the extraction solvent.After extraction，the specimen was dehydrated，adsorbed，purified，and determined by the selected ion monitor（SIM）after gas-phase separation.The test results of the fish tissue samples showed that GSM and 2-MIB were good linear in the range of 0.50 μg/L-500.00 μg/L，with correlation coefficients R2≥0.999.The limits of detection were 0.37 ng/g and 0.51 ng/g，respectively，and the limits of quantification of the methods were 1.23 ng/g and 1.69 ng/g，respectively.Three levels of standardization experiments showed that the spiked recoveries of GSM and 2-MIB in the method were 99.7%-115.7%（n=3），and the relative standard deviation（RSD）was 3.0%-14.0%.The method met the testing of different fish samples.