HPLC-MS/MS Determination of Metabolites of Nitrofurans in Aquatic Products

The method of HPLC-MS/MS was applied to the determination of metabolites of nitrofurans in aquatic products.The protein-bound metabolites were liberated from the sample by hydrolysis in dil.HCl medium and derivatized simultaneously with 2-nitrobenzaldehyde.The derivatized products were extracted with ethyl acetate and purified with n-hexane,which was then used for HPLC-MS/MS determination.It was proved that the extraction should be carried out in the medium having its pH value around 7.0 and the operation (including the purification) should be kept away from sunshine.A mixture containing 17 mmol·L-1 HOAc and acetonitrile was used as mobile phase in HPLC separation and the ESI+ with MRM was used in MS/MS determination.Detection limits (3S/N) found were in the range of 0.1-0.5 μg·kg-1.Standards of 4 metabolites with concentration of 0.5 μg·kg-1 were added to 3 different kinds of aquatic products and tested for the recovery,values of recovery obtained were in the range from 86% to 102%.Values of RSD′s (n=8) found were less than 13%.