[Malachite green and leucomalachite green in water determined by liquid chromatography/tandem mass spectrometry method].

OBJECTIVE: A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed to quantitate and confirm the presence of malachite green and leucomalachite green in water using isotope internal standard dilution technique. METHODS: Water samples were spiked with deuterium labeled isotope internal standards, extracted and cleaned by SPE of SCX column. Quantitative results were based on MRM. RESULTS: The calibration curve of malachite green and leucomalachite green showed good linearity in the range of 0.2 - 5 microg/L with correlation coefficient of 0.9993 and 0.9991 respectively. The detection limits of the method were 0.001ng/L for both malachite green and leucomalachite green. The average recoveries at three dose levels (0.2, 5 and 10 ng/kg) ranged from 93.6% - 107.5% with RSD from 3.7% to 9.3%. CONCLUSION: The method could identify and quantify malachite green and its metabolite leucomalachite green in fish pond water with satisfactory sensitivity, accurate and precision.