Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava #6, San Luis Potosí, S.L.P., 78290, Mexico.
J Hazard Mater. 2012 Dec;243:130-8. doi: 10.1016/j.jhazmat.2012.10.010. Epub 2012 Oct 13.
The advanced oxidation of paracetamol (PAM) promoted by TiO(2)/UV system in aqueous medium was investigated. Monitoring this reaction by HPLC and TOC, it was demonstrated that while oxidation of paracetamol is quite efficient under these conditions, its mineralization is not complete. HPLC indicated the formation of hydroquinone, benzoquinone, p-aminophenol and p-nitrophenol in the reaction mixtures. Further evidence of p-nitrophenol formation was obtained following the reaction by UV-vis spectroscopy. Continuous monitoring by IR spectroscopy demonstrated the breaking of the aromatic amide present in PAM and subsequent formation of several aromatic intermediate compounds such as p-aminophenol and p-nitrophenol. These aromatic compounds were eventually converted into trans-unsaturated carboxylic acids. Based on these experimental results, an alternative deacylation mechanism for the photocatalytic oxidation of paracetamol is proposed. Our studies also demonstrated IR spectroscopy to be a useful technique to investigate oxidative mechanisms of pharmaceutical compounds.
研究了在水介质中 TiO(2)/UV 体系促进对乙酰氨基酚（PAM）的高级氧化。通过 HPLC 和 TOC 监测该反应，结果表明，尽管在这些条件下对乙酰氨基酚的氧化效率相当高，但它的矿化并不完全。HPLC 表明反应混合物中形成了对苯二酚、苯醌、对氨基酚和对硝基苯酚。通过紫外-可见光谱法对反应进行进一步检测，证实了对硝基苯酚的形成。通过连续的红外光谱监测，证明了 PAM 中存在的芳酰胺的断裂以及随后形成了几种芳族中间化合物，如对氨基酚和对硝基苯酚。这些芳族化合物最终转化为反式不饱和羧酸。基于这些实验结果，提出了一种用于光催化氧化对乙酰氨基酚的替代脱酰基机制。我们的研究还表明，红外光谱是研究药物化合物氧化机制的有用技术。
