二氧化锡中空微球用于快速灵敏检测硫化氢

以氨基酚醛树脂球作模板,通过一种简单的模板法制备了具有中空微球(HMS)结构的二氧化锡;将其涂覆于氧化铝陶瓷管金电极表面,制得一种新型薄膜式硫化氢传感器.采用X射线衍射(XRD)及透射电子显微镜(TEM)表征了材料的微观结构和形貌,并考察了二氧化锡中空微球(Sn O2HMS)的气敏性能.结果表明,二氧化锡中空微球对硫化氢气体表现出良好的气敏特性.在最佳工作温度(200℃)下,所制作的传感器对142.6 mg/m3硫化氢的响应值高达97.13%,响应时间为22 s.该传感器对硫化氢的响应线性范围为0.2852~142.6 mg/m3,相关系数为0.9931,检出限达到0.1549 mg/m3,且几乎不受环境湿度和温度的影响,具有良好的重现性和选择性.对养殖场中硫化氢气体连续监测10个月后,传感器响应信号衰减了5.4%,表明该传感器具有长期稳定的使用寿命,可实现远程监测的实际应用.     

钒(Ⅴ)-5-Br-PADAP-H2O2-吐温-80显色体系的研究与应用

研究了在非离子表面活性剂吐温 - 80存在下 ,钒 ( )与 2 - [(5 -溴 - 2 -吡啶 ) -偶氮 ]- 5 -二乙氨基苯酚 (5 -Br- PADAP)及 H2 O2 的显色反应。实验表明 :在 p H1.5— 4 .0范围内 ,钒 ( )与 5 - Br- PADAP、H2 O2 形成稳定的配合物 ,最大吸收峰位于 5 95 nm处 ,表观摩尔吸光系数为 6 .2× 10 4L· mol-1· cm-1,配合物组成比为钒 ( )∶ 5 - Br- PADAP∶ H2 O2 =1∶ 1∶ 1。钒含量在 0— 15μg/ 2 5 m L范围内服从比耳定律。该方法灵敏度较高 ,用于合成水样中钒的测定 ,结果令人满意。     

Separation of aminophenol isomers in polyelectrolyte multilayers modified PDMS microchip

The separation of three kinds of aminophenol isomers were achieved within 1 min in polyelectrolytes multilayers modified PDMS microchips by layer-by-layer assembly with electrochemical detection (EC). Two polyelectrolytes, poly(dially dimethyl ammonium chloride) (PDDA) and poly(sodium-4-styrene-sulfonate) (PSS) were used to form polyelectrolyte multilayers (PEMs). The surface characteristic of the modified microchip was studied by XPS. The electroosmotic flow (EOF) on PEMs modified PDMS microchips was more stable than that of the native PDMS microchips and the adsorption of samples was greatly reduced on PEMs modified PDMS microchips during the electrophoretic process. The column efficiencies on PEMs modified microchip were increased by 100 times and the signals enhanced by 2 times compared with those of native microchips. The separation conditions such as running buffer pH, running buffer concentration and separation voltage were also optimized.     

Electrocatalytic Determination of 6‐Tioguanine at a p‐Aminophenol Modified Carbon Paste Electrode

A p‐aminophenol modified carbon paste electrode (p‐APMCPE) was constructed for determination of an anticancer drug 6‐thioguanine (6‐TG). The cyclic voltammogram showed that the electrocatalytic oxidation of 6‐TG at the surface of p‐APMCPE occurs at a potential about 840 mV less positive than at an unmodified electrode. Square‐wave voltammetry results presented that the electrocatalytic oxidation peak currents of 6‐TG in pH 9.0 had two linear dynamic ranges in the range of 0.2 to 8.0 and 8.0 to 350.0 μM 6‐TG with a detection limit of 0.08 μM. The kinetic parameters such as electron transfer coefficient (α) and rate constant were determined for the chemical reaction between 6‐TG and p‐aminophenol. Finally, this method was evaluated for the determination of 6‐TG in 6‐thioguanine tablets and urine samples.     

Clauson–Kaas-Type Synthesis of Pyrrolyl-phenols,from the Hydrochlorides of Aminophenols,in the Presence of Nicotinamide

A facile Clauson–Kaas-type pyrrolyl-phenol synthesis has been achieved in the presence of nicotinamide, which is inexpensive and nontoxic. The starting material is aminophenol hydrochloride. This is advantageous in certain cases because it is the only isolatable form of the corresponding aminophenol.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

New Determination Scheme of p‐Aminophenol by MnO2 Modified Electrode Coupled with Flow Injection Analysis

New determination scheme of p‐aminophenol by using MnO₂ as a preoxidant is demonstrated in this work. In the flow injection system, the p‐aminophenol is oxidized to quinoneimine by MnO₂ at up‐stream, which can be detected at a suitable reductive potential. After optimization, the linear range of PAP is started from 1 μM to 30 μM (R²=0.999), the estimated detection limit (S/N=3) is 0.28 μM. Two real samples are studied and excellent recoveries are achieved by using standard addition method.     

Solvent- and Catalyst-Free Synthesis of New Unsymmetrical Multidentate Thio-bis-aminophenol Ligands by Mannich Condensation

A one-pot, three-component, Mannich condensation of electron-rich aromatic compounds such as 5-methyl-2-hydroxyphenyl sulfide, 2-aminopyrimidine, and various aromatic aldehydes were used to prepare a series of new unsymmetrical multidentate aminophenol ligands. These compounds were synthesized in solvent-free conditions as a fast, simple, convenient, and uncatalyzed method. Details of the reaction conditions are discussed.     

Electrochemical Glutathione Sensor Based on Electrochemically Deposited Poly‐m‐aminophenol

Preparation and characterization of electrodes suitable for determination of glutathione is reported in this study. For this poly‐m‐aminophenol (PmAP), poly‐o‐aminophenol, and poly‐p‐aminophenol were electrochemically deposited from aqueous solution on the surface of glassy carbon (GC) electrode by potential cycling in the range of +0.2–+1.0 V. The modified GC electrodes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy, contact angle measurement and ellipsometry. It was found that poly‐m‐aminophenol modified GC electrode (PmAP/GC‐electrode) is most suitable for electroanalytical determination of glutathione. An electroanalytical system for the determination of glutathione based on the PmAP/GC‐electrode was developed. The analytical system was characterized by low limit of detection, good stability, high sensitivity and wide linear detection range.     

NICKEL(II) AND EUROPIUM(III) COMPLEXES OF THE AMINOPHENOL LIGAND: 2-(DIETHYLAMINO)METHYLPHENOL (N∼OH). CRYSTAL STRUCTURES OF THE Ni(N∼O)2 AND [Eu(NO3)3(HN∼O)2]2 COMPLEXES

Abstract

The first Ni(II) compounds with aminophenol ligands were synthesized by reaction of 2-diethylaminomethylphenol and 2-diethylaminomethyl-4-methylphenol (N ～ OH) with dehydrated NiCl₂ in ethanol. They were characterized as tran-square planar Ni(N ～ O)₂ complexes by NMR and IR spectroscopies, mass spectrometry, elemental analysis and X-ray structure determination. When the ligand was reacted with Eu(NO₃)₃, the new dimeric complex [Eu(NO₃)₃(HN ～ O)₂]₂ was isolated. Elemental analysis, IR, magnetic moment and X-ray diffraction indicated that in this case formally neutral aminophenol ligands, in their zwitterionic form, are attached to the metal center through the phenolato oxygen and act either as bridging or as terminal groups. Their protonated amino substituents are involved in strong N—H—O hydrogen bridging. The metal shows nine-coordination, the coordination sphere of each europium being completed by three NO₃ groups.     

气相色谱-质谱法同时测定氧化型染发剂中的17种染料

建立了氧化型染发剂中17种染料中间体(包括苯二胺类、氨基酚类、苯二酚类、萘酚和氨基吡啶类等)的气相色谱-质谱检测方法. 采用体积分数为50%的乙醇超声提取染发剂中的染料中间体, 加入还原剂连二亚硫酸钠防止待测物变质, 选择DB\|WAX毛细管柱实现了在25 min内同时分离17种水溶性和醇溶性染料. 结果表明, 本方法对所测物质的检出限(LOD)为2～380 mg/kg, 定量限(LOQ)为7.5～1267.5 mg/kg. 在1, 2, 10, 20或100倍LOQ 4个添加水平下的平均回收率在81.1％～103.7％之间, 相对标准偏差(n=6)在0.67%～3.73%之间.