Rapid and accurate quantification and analysis of nitrofuran metabolites residues in aquatic products by ultra-high performance liquid chromatography–tandem mass spectrometry

Nitrofurans, a kind of banned antibiotics for their serious toxic side effects, have often been found in aquatic products in the past and are still found nowadays which were a severe threat for human health. A rapid quantization of nitrofuran metabolites residues in aquatic products by ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was developed in this study. The experimental operation consisted of an acid-catalyzed release of protein-bound metabolites, followed by derivatization with 2-chlorobenzaldehyde (2-CBA) and then extraction with ethyl acetate before analysis by positive electrospray ionisation (ESI+) with multiple reaction monitoring (MRM) type. 2-CBA was employed as derivatization reagent in this study, which greatly reduced the derivatization time. The linearity range for the four analytes were 0.25–50 μg kg−1 with good determination coefficients (R2 > 0.9982). The limit of detection (LOD) were 0.1 μg kg−1, 0.1 μg kg−1, 0.3 μg kg−1, 0.3 μg kg−1 and the limit of quantification (LOQ) were 0.3 μg kg−1, 0.3 μg kg−1, 0.9 μg kg−1, 0.9 μg kg−1 for AOZ, AMOZ, SEM, and AHD, respectively. Recovery rates were ranged from 90% to 114% for fortified samples at levels of 1.0 μg kg−1, 5.0 μg kg−1 and 10 μg kg−1 with relative standard deviation values ranging from 1.6% to 5.8%. The developed method was successfully applied in 100 aquatic products for NFs metabolites detection and the results were further confirmed by the national standard GB/T 21311-2007 method.