Determination of Malachite Green in Fishery Products by Resonance Rayleigh Scattering Method

In an experiment reported in this paper,the resonance Rayleigh scattering(RRS) of malachite green(MG) or tungstate anion was very weak in pH 4.4 HC1-NaAc buffer medium,but when MG cation reacted with WO2-4 anion to form an ion association complex,its RRS dramatically increased and a new RRS spectrum appeared with the RRS peaks at 339 nm,591 nm and 451 nm.The intensity of RRS(ΔI) was directly proportional to the concentration of malachite green in the range of 0.06-2.78 μg/mL at the maximum scattering peak of 339 nm.The method was shown to be sensitive and the detection limit for MG was 18.1 ng/mL.Thus a new method for the determination of MG was developed.When applied to the determination of malachite green residues in the flesh of fish,this method gave satisfactory results similar to those of the HPLC method.