| A method was developed for the determination of residual amantadine,rimantadine and memantine in eggs by dispersive solid phase extraction and liquid chromatography with tandem mass spectrometry.The satisfactory separation was obtained after optimizing composition of mobile phase and column temperatures for rimantadine and memantine isomers.The samples were extracted with acetic acid acetonitrile,then purified by dispersive solid phase extraction method with PSA and C18 sorbent.After purification,the extract was dried under nitrogen,and the residues were dissolved in 0.1% formic acid-methanol(90∶10) and filtered through a 0.22 μm filter.The target compounds were analyzed by LC-MS/MS on an Acquity BEH C18 column using a mixture of 0.1% formic acid-methanol as mobile phase with gradient elution.The mass spectrometer was operated under multiple reaction monitoring(MRM) mode in positive mode.The samples were quantified by the isotope dilution and internal standard methods.Good linearities were obtained for amantadine,rimantadine and memantine at a concentration range of 0.10-10.0 μg/L with correlation coefficients more than 0.999.The limits of detection for three drugs were all 0.15 μg/kg,and the limits of quantitation were 0.50 μg/kg.The recoveries of three drugs in eggs at three spiked levels(0.50,0.75 and 1.0 μg/kg) were in the range of 96.2%-105.9%,with intra-assay relative standard deviations of 2.7%-4.5% and inter-assay relative standard deviations of 4.1%-5.3%.The results demonstrated that the method was suitable for the determination of amantadine,rimantadine and memantine in eggs. |