Abstract：
Acetaminophenol, commonly recognized as paracetamol (considered safer than aspirin) is formed by nitration of phenol (4-nitrophenol (4-NP)) for its conversion to 4-aminophenol (4-AP), followed by the acetylation for the final product. As 4-NP is an intermediate product in acetaminophenol (paracetamol) production from phenol the dynamic analysis of acetylation of amine group is important. This study focuses on the feasibility of spectroscopic studies to monitor the removal of 4-NP using sodium borohydride (NaBH4) probe reaction in the presence of silver, gold, and bimetallic Ag/Au nanoparticles. UV-visible absorbance and fluorescence spectroscopy measurements reveal the formation of 1,4-benzoquinone (BQ), hydroquinone (HQ), and phenol (Ph) as the final products, in addition to the formation of typically reported 4-AP. The intermediates of NaBH4 seem to play a significant role in the formation of BQ, which converts to HQ in the basic medium followed by the formation of phenol in an acidic medium. Complete kinetic analysis with respect to spectroscopic studies of the standard compounds is presented. Similar results were obtained with 4-NP spiked river and seawater samples. The present findings may lead to catalytic benchmarking that can differ from most of the current practices and highlight the importance of adopting a holistic approach towards the fundamental understanding of 4-NP catalytic reduction that must take into account the concentration of NaBH4 and pH interdependencies.
摘要：
对乙酰氨基酚，通常被认为是扑热息痛（被认为比阿司匹林更安全）是通过苯酚（4-硝基苯酚（4-NP））的硝化转化为4-氨基苯酚（4-AP）形成的，然后进行最终产物的乙酰化。由于4-NP是由苯酚生产对乙酰氨基酚(对乙酰氨基酚)的中间产物,因此胺基乙酰化的动态分析是重要的。本研究着重于光谱研究的可行性，以监测在银存在下使用硼氢化钠（NaBH4）探针反应去除4-NP，黄金,和双金属Ag/Au纳米颗粒。紫外可见吸收和荧光光谱测量揭示了1,4-苯醌（BQ）的形成，氢醌(HQ),和苯酚（Ph）作为最终产品，除了形成典型报道的4-AP。NaBH4的中间体似乎在BQ的形成中起重要作用，其在碱性介质中转化为HQ,随后在酸性介质中形成苯酚。提出了有关标准化合物光谱研究的完整动力学分析。使用4-NP加标的河流和海水样品获得了类似的结果。Thepresentfindingsmayleadtodalyticalbenchmisingthatcandifferfrommostofthecurrentpracticesandhighlightingtheimportanceofadoptingatowarateapproachtowardthefundamentalunderstandingof4-NP催化反应thatmusttakeintoaccounttheconcentrationof
