Determination of Residual Amounts of Malachite Green in Grass Carp with Fluorescence Probe of Water Soluble Fluorescein

Based on the fluorescence quenching action of malachite green (MG) on water soluble fluorescein (SF), a method for determination of residual amount of MG in grass carp using SF as fluorescence probe was proposed. It was found that in a B-R buffer solution, linear relationship between the magnitude of fluorescence quenching and mass concentration of MG was kept in the range within 80 μg·L-1, with detection limit (3S/N) 0.01 μg·L-1. Recovery of the method was tested by standard addition method, values of recovery found were in the range of 68.4%-83.3% with RSD (n=6) in the range of 3.4%-5.3%.