HPLC-MS/MS Determination of Residual Amounts of Malachite Green Crystal Violet and Their Leucobases in Eel

High performance liquid chromatography in hyphenation with tendem mass spectrometry (HPLC-MS/MS) was applied to the determination of residual amounts of malachite green (MG),crystal violet (CV) and their leucobases (LMG and LCV).Sample of eel was extracted with acetonitrile,which was defatted,concentrated and purified.The residue obtained was dissolved in the mobile-phase solution and separated on the Acquity UPLCTM BEH C18 column.The eluate was used for tandem MS determination.Deuterium substituted MG and LMG were used as internal standards.Linear relationships were obtained in the ranges of 0.1~10 μg·L-1 for either of the MG,LMG,CV and LCV.Tests for recovery were made by addition of 0.5 μg·kg-1 and 2 μg·kg-1 of standards of MG,LMG,CV and LCV to blank flesh samples,and the results obtained were in the range of 86.5%-91.8%.Detection limits obtained were 0.1 μg·L-1 for MG and LMG,and 0.5 μg·L-1 for CV and LCV.Values of RSD′s (n=7) found for the determinations were ≤7%.