分散固相萃取净化-液相色谱-质谱联用测定水产苗种中硝基呋喃类代谢物残留量

建立分散固相萃取净化-液相色谱-质谱法测定水产苗种中氨基脲、5-甲基吗啉-3-氨基-2-噁唑烷基酮、3-氨基-2-噁唑烷基酮、1-氨基-2-内酰脲，4 种硝基呋喃类代谢物残留量的方法。样品经甲醇-水（8∶1，V/V）溶液洗涤后，盐酸溶液水解，以2-硝基苯甲醛作为衍生化试剂，乙酸乙酯萃取，浓缩，分散固相萃取净化，采用液相色谱-质谱仪、多反应监测扫描模式检测和同位素内标定量。4 种硝基呋喃类代谢物在0.5～20 μg/L范围内线性相关系数大于0.997，检出限0.1 μg/kg，回收率90.5%～104.5%，相对标准偏差1.56%～8.08%。本方法灵敏、高效、简单、重复性好，满足硝基呋喃类代谢物的检测要求。

Determination of Nitrofuran Metabolite Residues in Aquatic Fingerlings by High Performance Liquid Chromatography-Mass Spectrometry with Dispersive Solid Phase Extraction

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.