Determination of malachite green and crystal violet in fish by ultrasound-assisted extraction combined with dispersive liquid-liquid microextraction

A new method based on ultrasonic-assisted extraction(UAE)and dispersive liquid-liquid microextraction(DLLME)with high performance liquid chromatography(HPLC)was proposed for the analysis of malachite green(MG)and crystal violet(CV)in fish meat.The effect of solvent,the extraction time,the number of extraction,extractant and dispersant were studied.After being extracted by UAE,enriched and purified by DLLME,the fish meat sample was tested by HPLC to determine the residue of malachite green and crystal violet.Under the optimized experimental conditions,linear response data were obtained in the concentration range of 0.002~1 μg/mL for MG,CV with correlation coefficients 0.997 7~0.998 8.The detection limit was 3.6 μg/kg for MG and 2.4 μg/kg for CV.The recovery rates were 90.17%~103.86%,relative standard deviations were 5.51%~14.26%.This new established method is simple and fast,accurate and feasible.It can be successfully applied for the determination of MG and CV in fish.