Abstract:

In this study, we presented a high performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method for determining 4 nitrofuran metabolites in 115 fish or fry products, namely 1-aminohydantoin hydrochloride (AHD), 3-amino-5-morpholinomethyl-2-oxazolidineone (AMOZ), 3-amino-2- oxazolidinone (AOZ) and semicarbazide (SEM). Samples were subjected to hydrolysis, derivation and clean-up prior to HPLC-MS/MS analysis. The analysis was carried out in the multi reaction monitoring (MRM) mode and internal standard isotope dilution method was used for quantification. Calibration curves for the analytes exhibited good linearity over the concentration range from 0.5 to 20 ng/mL and their limits of detection were all 0.25μg/kg. Average recoveries for them spiked at 3 levels ranged from 89.0% to 117.2%, with a RSD of less than 10%. Nitrofuran metabolites residues in fry were found much higher than those in adult fish. The detection rate of AOZ in large yellow croaker fry was 62%, with a maximum residue of 3890μg/kg; however, for large yellow croaker, the detection rate and the maximum residue were both comparatively lower, 17% and 2.81μg/kg, respectively. Less nitrofuran metabolites residues were detected in fresh water fish than in their sea counterpart.

Key words: nitrofuran metabolites, high performance liquid chromatography-tandem mass spectrometry, fish and fry products