The 5-nitro-2-furaldehyde (5-NF) is an aldehyde aromatic organic compound that has been envisaged as an alternative marker for detecting nitrofurazone treatment abuse and to avoid the false positive results induced by the semicarbazide. Analyzing 5-NF presents challenges, and its derivatization reaction with hydrazine reagents is required to enhance the capability of its detection and its identification. This study aims at developping an analytical method for 5-NF determination in trout muscle samples based on chemical derivatization prior to analysis by liquid chromatography–tandem mass spectrometry. Four commercially available hydrazine reagents, namely: N,N-Dimethylhydrazine (DMH), 4-Hydrazinobenzoic acid (HBA), 2,4-Dichlorophenylhydrazine (2,4-DCPH) and 2,6-Dichlorophenylhydrazine (2,6-DCPH) were proposed for the first time as derivatizing reagents in the analysis of 5-NF. The derivatization reaction was simultaneously performed along with the extraction method in acidic condition using ultrasonic assistance and followed by liquid extraction using acetonitrile. The efficiency of the chemical reaction with 5-NF was examined and the reaction conditions including the concentration of hydrochloric acid, pH, temperature, reaction time and the concentration of the derivatizing reagents were optimized. Experiments with fortified samples demonstrated that 2,4-DCPH derivatizing reagent at 20 mM for 20 min of ultrasonic treatment under acidic condition (pH 4) gave an effective sample derivatization method for 5-NF analysis. Under the optimized conditions, the calibration curves were linear from 0.25 to 2 μg kg with coefficient of determination >0.99. The recoveries ranged from 89 % to 116 % and precision was less than 13 %. The limit of detection and quantification were 0.1 and 0.2 μg kg, respectively.

中文翻译：

---

液相色谱-串联质谱法测定鳟鱼肌肉中5-硝基-2-糠醛的新型衍生试剂

5-硝基-2-糠醛 (5-NF) 是一种醛类芳香族有机化合物，被设想作为检测呋喃西林治疗滥用的替代标记物，并避免由氨基脲引起的假阳性结果。 5-NF的分析存在挑战，需要通过肼试剂进行衍生化反应以提高其检测和鉴定的能力。本研究旨在开发一种在液相色谱-串联质谱分析之前基于化学衍生化测定鳟鱼肌肉样品中 5-NF 的分析方法。四种市售肼试剂，即：N,N-二甲基肼（DMH）、4-肼基苯甲酸（HBA）、2,4-二氯苯肼（2,4-DCPH）和2,6-二氯苯肼（2,6-DCPH）首次提出作为 5-NF 分析中的衍生试剂。衍生化反应与在酸性条件下使用超声波辅助的提取方法同时进行，然后使用乙腈进行液体提取。考察了与5-NF的化学反应效率，并对盐酸浓度、pH、温度、反应时间和衍生剂浓度等反应条件进行了优化。对强化样品的实验表明，20 mM 的 2,4-DCPH 衍生剂在酸性条件（pH 4）下超声处理 20 分钟为 5-NF 分析提供了有效的样品衍生化方法。在优化条件下，校准曲线在0.25至2μg·kg范围内呈线性，测定系数>0.99。回收率范围为 89% 至 116%，精密度低于 13%。检测限和定量限分别为0.1和0.2μg·kg。