Rapid determination of malachite green,crystal violet and their metabolites in fish by liquid chromatography-tandem mass spectrometry

Objective To develop a rapid method to determine the residues of malachite green( MG),leucomalachite green( LMG),crystal violet( CV) and leucocrystal violet( LCV) in fish by liquid chromatography-tandem mass spectrometry( LC-MS / MS). Methods The target analytes were extracted from homogenized fish sample with acetonitrile and ammonium acetate, purified on neutral alumina solid – phase extraction( SPE) cartridge,separated by a Waters XBridge C18 column( 150 mm × 2. 1 mm i. d.,3. 5 μm),and detected by electrospray ionization in positive ion mode( ESI +) in multiple reaction monitoring( MRM) mode. D5-MG and D6-LMG were used as internal standard for quantitative determination. Results The calibration curves showed good linearity for MG,LMG,CV and LCV with the correlative coefficients( r) more than 0. 99. The limits of detection for all were 0. 1 μg / kg. The average recoveries at 0. 5 μg / kg,1. 0 μg / kg and 2. 0 μg / kg ranged from 78% to 106% with the relative standard deviations between 2. 6% and 6. 3%. Conclusion The method is simple and rapid. It is suitable for determination of MG,LCV and their metabolites in fish.