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An Ionic Liquid Bulk-Modified Carbon paste Electrode and Its Electrocatalytic Activity toward p-aminophenol

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Chinese Journal of Chemistry 2007年第11期25卷 1652-1657页

作者：张亚郑建斌 Institute of Analytical Science Shaanxi Province Key Laboratory of Electroanalytical Chemistry Northwest University Xi'an Shaanxi 710069 China

An ionic liquid bulk-modified carbon paste electrode （M-CpE） has been fabricated by using 1-heptyl-3-methylimidazolium bromide as a modifier. Cyclic voltammetry （CV） and differential pulse voltammetry （DpV） were used to evaluate the electrocatalytic activity of the proposed electrode by choosing p-aminophenol （p-Ap） as a model compound. Both at a bare carbon paste electrode （CpE） and the M-CpE, p-Ap yielded a pair of redox peaks in 0.1 mol·L^-1 phosphate buffer solution （pBS, pH 7.0）. At the CpE, the peak-to-peak potential separation （AEp） was 0.233 V, while at the M-CpE the AEp was decreased to 0.105 V. Furthermore, the current response to p-Ap at the M-CpE was 10.2 times of that at the CpE by DpV. The electron transfer rate constant （ks） ofp-Ap at the M-CpE was 13.3 times of that at the CpE. Under the optimal condition, a linear dependence of the catalytic current versus p-Ap concentration was obtained in the range of 2.0× 10^- 6 to 3.0× 10^- 4 mol·L^-1 with a detection limit of 6.0× 10^-7 mol·L^-1 by DpV. In addition, compared to other modified method the proposed electrode exhibited distinct advantages of simple prapartion, surface renewal, good reproducibility and good stability. It has been used to determine p-Ap in simulated wastewater samples.

关键词： voltammetry ionic liquid carbon paste electrode electrocatalysis p-aminophenol

Layered CuNi-Cu_(2)O/NiAlO_(x) nanocatalyst for rapid conversion of p-nitrophenol to p-aminophenol

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Nano Research 2021年第12期14卷 4616-4624页

作者： Lin Fu Wei Zhou Ming Wen Qingsheng Wu Weiying Li Dandan Wu Quanjing Zhu Jiaqi Ran panpan Ren School of Chemical Science and Engineering College of Environmental Science and EngineeringKey Laboratory of Yangtze River Water EnvironmentMinistry of EducationShanghai Key Laboratory of Chemical Assessment and SustainabilityTongji UniversityShanghai200092China School of Materials Science and Engineering Shanghai Institute of TechnologyShanghai201418China

In order to well arrange active sites and avoid byproducts, the reasonable structured carrier nanocatalyst plays a crucial role in high catalytic performance, but still remains a challenge. Herein, the layered CuNi-Cu_(2)O/NiAlO_(x) nanosheets have been constructed through hydrothermal synthesis followed by calcination and H_(2) reduction treatment process. The in-situ formed CuNi nanoalloys (NAs) and nano-Cu_(2)O were evenly distributed on the bilateral surface of layered NiAlOx nanosheets. Based on the planar structure of nanosheet, the synergy between catalytic active CuNi NAs and photocatalytic active nano-Cu_(2)O endows CuNi-Cu_(2)O/NiAlO_(x) nanosheets with rapid conversion efficiency for catalyzing p-nitrophenol (p-Np, 14 mg·L^(−1)) to p-aminophenol (p-Ap) in 32 s with the reaction rate constant k up to 0.1779 s−1, and no obvious performance decay can be observed even over 27 cycles. Moreover, high concentration of p-Np at 10 and 20 g·L^(−1) could be reduced to p-Ap within 14 and 20 min, respectively. Such designed nanoalloy/bimetal-oxide heterostructure can provide a solution for rapid conversion of aminoaromatics from nitroaromatics wastewater even at a large concentration range.

关键词： layered CuNi-Cu_(2)O/NiAlO_(x) heterostructure catalyst p-nitrophenol p-aminophenol

Synthesis of bifunctional pt/MgApO-5 catalysts and their catalytic performance in the hydrogenation of nitrobenzene to p-aminophenol

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Science China Chemistry 2010年第7期53卷 1514-1519页

作者： ShuFang Wang YaDan Jin BeiBei He YanJi Wang XinQiang Zhao Hebei Univ Technol Key Lab Green Chem Technol & High Efficient Energ Tianjin 300130 Peoples R China

MgApO-5 molecular sieves have been synthesized using diethylaminoethanol as the templating agent in a wide range of the MgO/Al2O3 *** samples were characterized by XRD,SEM,solid state NMR,FT-IR and *** MgApO-5 as acidic supports,bifunctional pt/MgApO-5 catalysts were prepared for hydrogenation of nitrobenzene to p-aminophenol (pAp).The results showed that the MgO/Al2O3 ratios influenced the Mg content and the acidity of MgApO-5 samples,thereby greatly affecting the catalytic performance of pt/MgApO-5 *** selectivity to pAp over pt/MgApO-5 was dependent on the amount of strong acid sites of *** the MgO/Al2O3 molar ratio was 0.5,the synthesized MgApO-5 sample exhibited the largest amount of strong acid and a highest pAp yield of 41.1% was achieved over pt/MgApO-5 catalyst.

关键词： aluminophosphate molecular sieve bifunctional catalyst p-aminophenol nitrobenzene hydrogenation

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Study on Free Radicals produced During the photolysis of p-aminophenol in Aqueous TiO_2 Suspension

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Chinese Science Bulletin 1994年第1期39卷 41-46页

作者：陈次平任新民陆道惠徐广智 Institute of photographic Chemistry Academia Sinica Beijing 100101 PRC Institute of Chemistry Academia Smica Beijing 100080 PRC

Recently, study on the photocatalytic degradation of harmful substances by usingsemiconductors has received much attention,because semiconductors, as a stable andinexpensive photocatalyst, may be effective for the degradation of pollutants from the stand-point of solar energy utilization, e.g. TiO2, the photoinduced holes with high oxidationpotential, may be used as strong oxidant to decompose a large number of

关键词： p-aminophenol titanium dioxide free radicals.

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Quality Control of paracetamol Generic Tablets Marketed in Benin and Search of Its Two Impurities p-aminophenol and p-Nitrophenol by HpLC-UV/Visible

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American Journal of Analytical Chemistry 2022年第11期13卷 449-460页

作者： Yemoa Loconon Achille Agbokponto Janvier Engelbert Assanhou Assogba Gabin Adetona pauline Doffon parfait Ganfon Habib Roland Marini Djang’eing’a Laboratoire de Chimie analytique et Analyse des Médicaments Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé. Université d’Abomey Calavi Cotonou Bénin Laboratoire de pharmacie Galénique et de Technologie pharmaceutique Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé Université d’Abomey Calavi Cotonou Bénin Laboratoire de pharmacognosie et de de phytothérapie Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé Université d’Abomey Calavi Cotonou Bénin Laboratoire de Chimie Analytique pharmaceutique Departement de Pharmacie Université de Liège (ULiège) Liège Belgium

In this work, we evaluated the quality of paracetamol generic tablets while seeking its two main impurities namely 4-para-aminophenol (4-Ap) and 4-para-nitrophenol (4-Np) which have nephrotoxic and teratogenic properties. Ninety-four (94) samples were collected at various levels of the medicine supply chain and illegal markets in Benin for quality control tests such as visual inspection, pharmacotechnical tests as mass variation, disintegration test, dissolution test, followed by HpLC UV-Vis identification and assay of paracetamol, 4-Ap and 4-Np. The analytes were separated on C18 Lichrocart column (250 mm × 4.0 mm i.d, 5 μm);the mobile phase was MeOH:10 mM ammonium acetate buffer pH 6.8 (35:65) pumped at a flow rate of 1 ml/min. The detection was done at 245 nm. Analysis of our results shows that 77.7% of the samples did not comply with the visual inspection test requirements, 2.1% did not pass the mass variation test, 24.3% of the sample batches didn’t comply with the disintegration test requirements. In addition none of these uncomply batches passed the dissolution test, even if the identification test indicated that all samples contained paracetamol. None contained 4-Np (acceptance limit p), while 3 of 94 samples contained 4-Ap but within acceptance limit (4-Ap p). As for the paracetamol assay, 80.9% complied with the specifications of the pharmacopoeias taken as reference (90% - 110%;USp). Further, broader studies should be conducted according to the same rules of good practice for a more comprehensive analysis of the situation. Generally the quality control of paracetamol in most African countries, particularly in Benin, is based on pharmacotechnical tests and paracetamol assay. This work, in addition to the usual tests, showed the importance to search for paracetamol and other drugs’ impurities during their routine quality control.

关键词： Quality Control Substandard Medicines paracetamol p-aminophenol p-Nitrophenol Benin

RECOVERY OF p-aminophenol (pAp) FROM AQUEOUS SOLUTION BY HYpER-CROSS-LINKED RESIN AND ITS USE FOR WASTEWATER TREATMENT

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Chinese Journal of Reactive polymers 2008年第1期17卷 18-28页

作者： ZHANG Haiyun LI Aimin School of the Environment and State Key Laboratory of Pollution Control and Resource Reuse Nanjing University Nanjing 210093 China Department of the Environmental Engineering Nanjing Institute of Technology Nanjing 211167 China Engineering Technology Research Center of Organic pollutants Control and Resource reuse of Jiangsu province Nanjing 210038 China

p-aminophenol （pAp）, a typical amphoteric compound, has been widely used as raw chemical material and important interrnediate in various fields. To study on the recovery of pAp, an experimental comparison of the adsorption and desorption properties of pAp onto three types of hyper-cross-linked resins in aqueous solutions was performed. This paper focuses on the static equilibrium adsorption and desorption behaviors, the adsorption thermodynamics, the column dynamic adsorption and desorption, and other influencing factors of adsorption, such as temperature and pH values. All the isothermal data fit well to the Freundlich model. The capacity of equilibrium adsorption for pAp on NG-10 is the highest within the temperature range 288K-318K, which may greatly contribute to the advantage in specific surface area, especially the micropore area, of the adsorbent. While in the desorption experiments, NG-9 achieved relative well regeneration efficiency whether by ethanol or by 4% hydrochloric acid. Furthermore, the results of column tests and field applications were also proved that NG-9 was an effective sorbent for the reclamation pAp from wastewater.

关键词： Adsorption p-aminophenol Hyper-cross-linked resin Recovery.

RECOVERY OF p-aminophenol (pAp) FROM AQUEOUS SOLUTION BY HYpER-CROSS-LINKED RESIN AND ITS USE FOR WASTEWATER TREATMENT

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Chinese Journal of Reactive polymers 2008年第Z1期 18-28页

作者： ZHANG Haiyun1,2 LI Aimin1,3 1. School of the Environment, and State Key Laboratory of pollution Control and Resource Reuse, Nanjing University, Nanjing 210093, China 2. Department of the Environmental Engineering, Nanjing Institute of Technology, Nanjing 211167, China 3. Engineering Technology Research Center of Organic pollutants Control and Resource reuse of Jiangsu province, Nanjing 210038, China

p-aminophenol （pAp）, a typical amphoteric compound, has been widely used as raw chemical material and important intermediate in various fields. To study on the recovery of pAp, an experimental comparison of the adsorption and desorption properties of pAp onto three types of hyper-cross-linked resins in aqueous solutions was performed. This paper focuses on the static equilibrium adsorption and desorption behaviors, the adsorption thermodynamics, the column dynamic adsorption and desorption, and other influencing factors of adsorption, such as temperature and pH values. All the isothermal data fit well to the Freundlich model. The capacity of equilibrium adsorption for pAp on NG-10 is the highest within the temperature range 288K318K,which may greatly contribute to the advantage in specific surface area, especially the micropore area, of the adsorbent. While in the desorption experiments, NG-9 achieved relative well regeneration efficiency whether by ethanol or by 4% hydrochloric acid. Furthermore, the results of column tests and field applications were also proved that NG-9 was an effective sorbent for the reclamation pAp from wastewater.

关键词： Adsorption p-aminophenol Hyper-cross-linked resin Recovery.

Acetaminophen metabolites p-aminophenol and AM404 inhibit microglial activation

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Neuroimmunology and Neuroinflammation 2018年第4期5卷 8-22页

作者： Wyatt T.Slattery Andis Klegeris Department of Biology University of British Columbia Okanagan CampusKelownaBC V1V 1V7Canada

Aim: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline, deposits of amyloid beta and neurofibrillary tangles. Inflammation facilitated by microglia, the resident immune cells of the brain, contribute to the pathogenesis of AD. Epidemiological data indicate that nonsteroidal anti-inflammatory drugs (NSAIDs), which are cyclooxygenase (COX) inhibitors, reduce the risk of developing AD when administered over the course of two or more years. The mechanisms underlying this protective effect are unknown. Acetaminophen (paracetamol), which is not effective as an inhibitor of COX in peripheral tissues, may provide similar protection without the adverse effects of chronic NSAID use. The beneficial effects of acetaminophen have been proposed to stem from its metabolites p-aminophenol and N-arachidonoylaminophenol (AM404), of which, AM404 possesses analgesic and antipyretic properties. The goal of this study was to compare the effects of acetaminophen and its metabolites on microglial immune function and to elucidate the molecular mechanisms engaged by these compounds. Methods: Lipopolysaccharide-stimulated BV-2 murine microglia were used as models. Microglial activation was monitored by their secretion of nitric oxide. Results: p-aminophenol and AM404 suppressed nitric oxide secretion from stimulated microglia more effectively than acetaminophen through pathways that were independent of COX inhibition, cannabinoid receptor type two (CB2) inhibition, and activation of transient receptor potential cation channel subfamily V member 1 (TRpV1). Conclusion: Since AM404 has been previously demonstrated to attenuate NF-kB activation, it is likely that the protective effects of acetaminophen against adverse microglia activation are mediated by its metabolites p-aminophenol and AM404 inhibiting this transcription factor.

关键词： Acetaminophen p-aminophenol AM404 neuroinflammation pharmacodynamics microglia

用对氨基苯酚改性的碳纳米管糊电极同时测定羟胺和苯酚(英文)

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催化学报 2013年第9期34卷 1768-1775页

作者： Ali A. Ensafi E. Heydari-Bafrooei B. Rezaei Department of Chemistry Isfahan University of Technology

A carbon paste electrode that was chemically modified with multiwall carbon nanotubes and p-aminophenol was used as a selective electrochemical sensor for the simultaneous detection of hydroxylamine (HX) and phenol. Cyclic voltammetry, double potential-step chronoamperometry, square wave voltammetry (SWV), and electrochemical impedance spectroscopy were used to investigate the use of p-aminophenol in the carbon nanotubes paste matrixes as a mediator for the electrocatalytic oxidation of HX and phenol in aqueous solution. The coefficient of electron transfer and catalytic reaction rate constant were determined using the electrochemical methods. Under optimized conditions, the electrocatalytic oxidation current peaks for HX and phenol increased linearly with concentration in the range of 0.5-180.0 and 10.0-650.0 μmol/L for HX and phenol, respectively. The detection limits for HX and phenol were 0.15 and 7.1 μmol/L, respectively. The anodic potential peaks of HX and phenol were separated by 0.65 V in SWV. Because of good selectivity and sensitivity, the present method provides a simple method for the selective detection of HX and phenol in practical samples such as water samples.

关键词： Hydroxylamine and phenol determination p-aminophenol Multiwall carbon nanotube paste electrode Voltammetry

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