碳纳米管复合聚对氨基吡啶修饰电极伏安法同时测定硝基酚异构体的研究

利用导电聚合物的分子识别性和碳纳米管奇特的物理化学性质, 制备了碳纳米管复合聚对氨基吡啶(SWNTs/POAP)修饰电极, 研究了邻、间、对硝基酚异构体同时在该电极上的电化学响应. 实验结果表明, 邻、间、对硝基酚异构体在SWNTs/POAP纳米电极界面具有不同的构象, 其氧化峰电位能够完全分开, 并能显著地提高电化学测定的灵敏度. 文中的SWNTs/POAP纳米电极制备简单方便, 可用于硝基酚位置异构体的同时电化学量测.     

α-环糊精复合碳纳米管电极对异构体的电催化行为

对异构体的测定与分离一直是化学家感兴趣的课题。硝基酚在环境样品检测中的重要性促进了其定性定量测定方法的发展。Umezawa等基于亲脂性的脂肪胺和杂环芳香胺类,首次制成了用于中性化合物的电位传感器;Piotrowski等制备出杯[4]吡咯液膜电极,此电极对p-硝基酚有选择性,并进一步研究了杯[4]吡咯的对称性对该修饰电极的灵敏度和选择性的影响。我们将碳纳米管(CNT)     

壳聚糖复合碳纳米管修饰超薄碳糊电极对硝基酚异构体的同时测定

以镍镉合金为基底,将壳聚糖滴涂在碳纳米管修饰的超薄碳糊电极表面制成电化学传感器(CTSCNTs-UTCPE),利用循环伏安法(CV)、半微分伏安法研究硝基酚异构体在该电极上的电化学行为。考察了底液种类、酸碱度、扫描速度、起始电位和富集时间对检测结果的影响。与镍铬合金电极、超薄碳糊电极(UTCPE)和碳纳米管修饰超薄碳糊电极(CNTs-UTCPE)相比,由于壳聚糖和碳纳米管的协同效应,硝基酚异构体在p H 5.72的B-R中氧化电流较高。在最佳条件下,传感器对邻、间、对硝基酚的检测范围分别为4.0×10-7~8.0×10-5mol/L,4.0×10-7~8.0×10-5mol/L,8.0×10-7~8.0×10-5mol/L;检出限(S/N=3)分别为2.3×10-7,2.9×10-7,6.7×10-7mol/L。该传感器显示出良好的稳定性和抗干扰性能,可实现对人工水样中硝基酚异构体的同时检测。     

聚甲苯胺蓝/碳纳米管/玻碳电极同时伏安法测定苯二酚异构体

通过电聚合甲苯胺蓝于多壁碳纳米管修饰玻碳电极上制备了聚甲苯胺蓝/碳纳米管/玻碳电极,研究了三种苯二酚异构体在该电极上的电化学行为。结果表明,修饰电极对苯二酚异构体的氧化表现出优异的电催化性能和选择性。考察了各种影响因素。在5.0×10-6～2.0×10-4mol/L的范围内,苯二酚异构体的阳极峰电流与其浓度有线性关系,建立了一种同时伏安分析3种苯二酚异构体的新方法。     

pMB/MWNTs/GC电极对水体中苯二酚异构体的同时测定

通过在多壁碳纳米管修饰玻碳电极上电聚合亚甲基蓝,制备了聚亚甲基蓝/碳纳米管/玻碳电极(pMB/MWNTs/GC)。用循环伏安法研究了3种苯二酚异构体在该电极上的电化学行为,结果表明,在pH7.0的磷酸盐缓冲溶液中,该修饰电极对苯二酚异构体的氧化表现出优异的电催化性能和选择性,对苯二酚、邻苯二酚和间苯二酚的氧化峰分别为0.104、0.203、0.609 V(vs.SCE),峰电位差值分别为99、406 mV。基于苯二酚异构体在pMB/MWNTs/GC修饰电极上的伏安行为,建立了苯二酚3种异构体同时分析的新方法。考察了各影响因素对测定的影响,最优实验条件下,在5.0×10-6~1.5×10-4mol.L-1范围内,3种苯二酚异构体的阳极峰电流与其浓度存在线性关系,检出限均为1.0×10-6mol.L-1。将该法用于水体及冲洗废液中苯二酚异构体含量的测定,结果满意。     

复合修饰电极测定p-硝基苯酚新方法的研究与探讨

将多壁碳纳米管分散在孔雀绿溶液中并滴涂在玻碳电极表面,再电聚合一层孔雀绿膜,制备了一种新型的聚孔雀绿/多壁碳纳米管复合膜修饰玻碳电极.用电化学方法对所制得的复合修饰电极进行了表征,并研究了p-硝基苯酚在该电极上的电化学行为.结果表明,所制备的复合修饰电极对P-硝基苯酚有良好的电催化作用,从而建立了一种直接测定P-硝基苯...     

化学修饰型硝基酚传感器的研究

采用Ｎａ－蒙脱石修饰碳糊电极制成的传感器,用于硝基酚类物质检测及定量分析。经研究发现,此种电极具有稳定性好,灵敏度高的优点,并且可用于邻,对硝基酚共存体系中两物质的分别定量检测。     

聚萘二胺修饰电极对痕量物质的检测

综述了聚萘二胺修饰铂电极、玻碳电极和碳糊电极用于检测痕量银离子、铅离子、亚硝酸根及硝酸根阴离子、过氧化氢、葡萄糖和胆甾醇等方面的研究成果，列举了这些电极的优异探测性能，并指出该类电极有望发展成为性能优异的检测电极和传感器。引用文献14篇。     

碳纳米管/对氯四苯基锰卟啉修饰电极同时测定二羟基苯异构体

制备了碳纳米管/对氯四苯基锰卟啉修饰的玻碳电极,研究了三种二羟基苯异构体在该修饰电极上的电化学行为。由于碳纳米管独特的性能及与对氯四苯基锰卟啉特殊的协同效应,异构体在该修饰电极上的氧化峰电流均显著增大。利用差分脉冲伏安法(DPV)可同时检测三种异构体,在pH=6.5的磷酸盐缓冲溶液(PBS)中,邻苯二酚(CC)、间苯二酚(RC)、对苯二酚(HQ)峰电流与其浓度分别在0.8～280.0μmol/L、1.5～85.0μmol/L和0.4～200.0μmol/L范围内呈良好的线性关系,其检出限分别为0.5μmol/L、1.0μmol/L和0.2μmol/L。该电极具有良好重现性和稳定性。     

碳纳米管修饰电极-人工神经网络同时检测一氯酚三种异构体

建立了碳纳米管修饰电极-人工神经网络同时检测-氯酚三种异构体的方法.在pH=7.0的磷酸盐缓冲溶液中,邻氯酚、间氯酚和对氯酚在碳纳米管修饰电极上均有一灵敏的不可逆氧化峰.采用微分脉冲溶出伏安法,在优化的实验条件下,邻氯酚、间氯酚和对氯酚的峰电位分别为624 mV、712 mV和632 mV,且浓度分别在2.07～103...     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -