Trace determination of malachite green in water samples using dispersive liquid–liquid microextraction coupled with high-performance liquid chromatography-diode array detection

A simple and reliable method has been developed for the rapid analysis of trace levels of malachite green from water samples using dispersive liquid–liquid microextraction and high-performance liquid chromatography-diode array detection. Factors relevant to the microextraction efficiency, such as the type and volume of extraction solvent, nature and volume of the disperser solvent, the effect of salt, sample solution temperature and the extraction time were investigated and optimised. Under the optimal conditions the linear dynamic range of malachite green was from 0.2 to 100.0 µg L−1 with a correlation coefficient of 0.9962. The detection limit and limit of quantification were 0.1 µg L−1 and 0.3 µg L−1, respectively. The relative standard deviation (RSD) was less than 2.6% (n = 5) and the recoveries of malachite green (5.0 µg L−1) from water samples were in the range of 99.2 ± 1.7%. Finally the proposed method was successfully applied for the analysis of malachite green from fish farming water samples.