Determination of Residual Amounts of Malachite Green and Its Metabolite in Aquatic Products by High Performance Liquid Chromatography with Fluorescence Detector

The residual malachite green (MG) in aquatic products was reduced to leuco-malachite green (LMG) with KBH4,and determined by high performance liquid chromatography (HPLC).MG was extracted from the homogenized tissue sample with acetonitrile in an acetate buffer medium of pH 4.5,separated and purified by liquid-liquid partition with CH2Cl2 and acidic alumina column.The Agilent SB-C18 (250 mm×4.6 mm,5 μm) column was used as stationary phase,and a mixed solution of acetonitrile and acetate buffer solution (mixed in the ratio of 6 to 94) was used as mobile phase.The eluate from the column was used for HPLC analysis with fluorescence detector.Linear relationship between the values of peak area and mass concentration of MG was obtained in the range of 1.0-500.0 μg·L-1,with detection limit (3S/N) of 0.46 μg·kg-1.Values of recovery and RSD′s (n=6) of the method found were in ranges of 78.0%-95.2% and 3.01%-5.98%.It was found that the transformation rate of MG into LMG was in the range of 99.1%-100.8%.