Abstract:

A method has been developed for the determination of four metabolites of nitrofuran, i.e. semicarbazide (SEM),
3-amino-5-morpholinomethyl-2-oxazolidineone (AMOZ), 3-amino-2-oxazolidinone (AOZ) and 1-aminohydantoin
hydrochloride (AHD) in aquatic fingerlings, by high performance liquid chromatography-mass spectrometry with dispersive
solid phase extraction. Samples were washed with a mixture of methanol-water (8:1, V/V), subjected to HCl acidolysis and
derivatized using 2-nitrobenzaldehyde. The derivative was extracted with ethyl acetate, then concentrated and cleaned up by
dispersive solid phase extraction. The analysis was carried out in the multi-reaction monitoring (MRM) mode and internal
standard isotope dilution method was used for quantification. Good linearity was obtained in the correlations between the
peak areas and concentrations of the four metabolites of nitrofuran antibiotics over the concentration range from 0.5 to
20.0 μg/L, with correlation coefficients above 0.997. The limits of detection (LODs) for the four compounds were all 0.1 μg/kg.
The range of average recoveries was between 90.5% and 104.5%, with relative standard deviations (RSDs) between 1.56%
and 8.08%. The efficient and simple method could be used to identify and quantify the metabolites of nitrofuran antibiotics
in aquatic fingerlings with satisfactory sensitivity and repeatability.

Key words: dispersive solid phase extraction, high performance liquid chromatography-mass spectrometry, aquatic fingerlings, nitrofuran metabolites