Abstract Introduction Some azo dyes, including Sudans I–IV and Para Red, are genotoxic and may be biotransformed to cancerogenic aromatic amines. They are banned as food and feed additives, but their presence has been detected in food. Aromatic amines are also considered potentially toxic. Online EC–MS is a promising tool to study the transformation mechanisms of xenobiotics such as azo dyes. The aim of the study was to investigate emulation of how azo dyes are enzymatically transformed to amines with EC–MS. Material and Methods The reduction reactions of five azo dyes (Sudans I–IV and Para Red) were conducted using a glassy carbon working electrode and 0.1% formic acid in acetonitrile. Reduction results were compared with the literature and in silico to select preliminary candidates for metabolites. The LC-MS/MS method was used to confirm results obtained by electrochemical reactor. Results A limited number of pre-selected compounds were confirmed as azo dyes metabolites – aniline for Sudan I, aniline and 4-aminoazobenzene for Sudan III, o-toluidine for Sudan IV, and 4-nitroaniline for Para Red. No metabolites were found for Sudan II. Conclusions Electrochemistry–mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation.

中文翻译：

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偶氮染料的电化学还原模拟其生物转化为毒性更大的产物

摘要 介绍 一些偶氮染料，包括苏丹红 I-IV 和对位红，具有遗传毒性，可能会被生物转化为致癌芳香胺。它们被禁止作为食品和饲料添加剂，但已在食品中检测到它们的存在。芳香胺也被认为具有潜在毒性。在线 EC-MS 是研究异生物质（如偶氮染料）转化机制的一种很有前途的工具。该研究的目的是研究偶氮染料如何通过 EC-MS 酶促转化为胺的模拟。材料和方法 使用玻碳工作电极和 0.1% 甲酸的乙腈溶液对五种偶氮染料（苏丹 I-IV 和对位红）进行还原反应。还原结果与文献和计算机进行比较，以选择代谢物的初步候选者。LC-MS/MS 方法用于确认电化学反应器获得的结果。结果 有限数量的预选化合物被确认为偶氮染料代谢物——苏丹 I 为苯胺，苏丹 III 为苯胺和 4-氨基偶氮苯，苏丹 IV 为邻甲苯胺，对位红为 4-硝基苯胺。没有发现苏丹 II 的代谢物。结论 电化学-质谱法成功应用于偶氮染料。这种方法可用于模拟偶氮染料的代谢，从而预测生物转化的产物。结论 电化学-质谱法成功应用于偶氮染料。这种方法可用于模拟偶氮染料的代谢，从而预测生物转化的产物。结论 电化学-质谱法成功应用于偶氮染料。这种方法可用于模拟偶氮染料的代谢，从而预测生物转化的产物。