共查询到20条相似文献,搜索用时 15 毫秒
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N. S. Kobotaeva E. E. Sirotkina E. V. Mikubaeva 《Russian Journal of Electrochemistry》2006,42(3):268-271
The oxidation of tritane dyes at a stationary glassy carbon electrode in methylene chloride is studied using voltammetry. It is shown that electron-donor-type dialkylamino-groups in the dye molecules favor the decreasing of the oxidation half-wave potentials; by contrast, the strong electron-acceptor-type nitroso-group contributes to their increasing. The Cl? anion and complex anion In Cl 4 ? , which are constituents of triphenylmethane dyes, are not oxidized in these conditions. 相似文献
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高效液相色谱-电喷雾串联质谱法快速分离鉴定纺织品中的9种致癌染料 总被引:4,自引:0,他引:4
采用高效液相色谱-电喷雾串联四极杆质谱(HPLC-ESI-MS/MS)在选择反应监测(SRM)模式下分离鉴定纺织品中禁用的9种致癌染料。用甲醇超声同时提取天然纤维和化学纤维上的染料,以5 mmol/L乙酸铵和乙腈为流动相在C18柱上于前段洗脱酸性红26、直接蓝6、直接黑38和直接红28(采用电喷雾质谱负离子模式检测),于后段洗脱碱性红9、碱性紫14、分散蓝1、分散橙11和分散黄3(采用电喷雾质谱正离子模式检测),实现了对不同种类纤维织品中分属4类性质不同染料的一次提取和一次分析检测。通过比较试样与标样的色谱保留时间和质谱图中子离子的相对丰度比,可准确鉴别纺织品中的致癌染料。 相似文献
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Carmen Ferrer Amadeo R. Fernández-Alba 《International journal of environmental analytical chemistry》2013,93(13-14):999-1012
A sensitive and accurate methodology was developed for the analysis of seven illegal dyes (Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Orange G, Sudan R and Para Red,) used as additives in food products, such as chilli powder and steak sauces. The analytical methodology consisted of solvent extraction with acetonitrile followed by liquid chromatography time-of-flight mass spectrometry detection. Accurate mass measurements were crucial in order to achieve a high degree of specificity for the target analytes in such complex samples. The dyes were effectively extracted from spice and sauce matrices achieving recoveries higher than 75%. Because of the excellent mass accuracy obtained for the target analytes (better than 2?ppm), no cleanup of the samples was required using this methodology, thus leading to a better precision and reproducibility of the results from the quantitative point of view. Calibration curves were linear and covered two orders of magnitude (from 0.01 to 1?mg?L?1) for all the compounds studied with the exception of Para Red. A detailed study of matrix effects is also included in this work, showing a clear improvement when dilution of the extracts was carried out. Method detection limits were in the low mg?kg?1 range, and the precision, calculated as the relative standard deviation, ranged from 5 to 15%. The methodology was successfully applied to market samples in a survey performed as part of a regional research programme organized by the Andalusian Health Service in Spain, and a positive confirmation for Sudan I was obtained in a chilli powder sample. 相似文献
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That T. Ngo 《Applied biochemistry and biotechnology》1985,11(4):257-268
An ultrasensitive chromogenic system for horseradish peroxidase (HRP) is described. The chromogenic substrate system consists
of 3-methyl-2-benzothiazolinone hydrazone (MBTH) andN-phenyldiethanolamine (PDEA). The oxidative coupling of MBTH and PDEA using H2O2 and HRP, respectively, as the oxidant and catalyst, yields a blue chromophore that most likely is an indamine dye. The chromophore
has a rather broad absorption band, with an absorption maximum at 602 nm. In 0.1M phosphate, 0.1M citrate buffer, pH 7.5,
the optimal concentrations of MBTH, PDEA, and H2O2 are, respectively, 0.5, 25, and 8 mM. Using this assay system, HRP can be determined in lower picomolar levels by either
a rate or fixed-time method. 相似文献
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辣根过氧化物酶活性膜结构及生物电催化性能 总被引:3,自引:0,他引:3
通过分子沉积法研究了在聚对苯二甲酸乙二醇酯(PET)表面及金电极表面组装辣根过氧化物酶(HRP)/聚对苯乙烯磺酸钠(PSS)多层生物活性膜,用原子力显微镜(AFM)研究了组装膜的表面形貌,并研究了组装膜的形貌、粗糙度和活性关系.应用循环伏安法(CV)研究了组装HRP膜后电极对H2O2的电化学催化还原作用.实验发现,采用亚甲基蓝(MB)溶液为介质,在H2O2浓度为0.2~5.0 mmol•L-1时,其响应电流对H2O2浓度变化基本呈线性. 相似文献
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建立了高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱(HPLC-LTQ/Orbitrap MS)筛查和确证生态纺织品中致癌染料的方法。样品在水浴(95 ℃)中用吡啶/水(1/1, v/v)振荡(150 r/min)提取,上清液过聚四氟乙烯(PTFE)滤膜后,CAPCELL PAK C18色谱柱(100 mm×2.0 mm, 5 μm)分离,以乙腈和5 mmol/L乙酸铵水溶液(含0.01%甲酸)、乙腈和5 mmol/L乙酸铵水溶液分别作为正、负电喷雾离子化(ESI)模式的色谱流动相梯度洗脱。在m/z 200~800范围内进行一级质谱全扫描。以准分子离子峰的精确质量数和提取的色谱图峰面积进行筛查分析和定量,以保留时间和数据依赖扫描(data-dependent scan)模式获得的子离子质谱图进行定性确证。9种染料的质量准确度小于5×10-6(5 ppm),线性良好,相关系数大于0.99,方法检出限为0.125~25 mg/kg。3个添加水平的回收率范围为62.13%~116.28%,相对标准偏差小于15%。应用该方法检测了棉、涤纶及混纺纤维等20余件纺织品样品中的致癌染料残留。该方法准确、可靠。 相似文献
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Fischer GM Ehlers AP Zumbusch A Daltrozzo E 《Angewandte Chemie (International ed. in English)》2007,46(20):3750-3753
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Antonio Domnech-Carb María Teresa Domnech-Carb 《Electrochemistry communications》2008,10(9):1238-1241
In situ atomic force microscopy (AFM) images of crystals of organic dyes alizarin, indigo and morin have been monitored during the course of their solid-state electrochemical oxidation/reduction in contact with aqueous acetate buffer. Such images indicate that proton-assisted reduction and oxidation processes are localized in a shallow layer in the vicinity of the particle/electrolyte interface, in agreement with expectances from the Lovric and Scholz model with significantly restricted proton diffusion across the solids. 相似文献
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Newly prepared azo compounds and several commercially available indicators were investigated for their applicability as colored isoelectric point (pI) markers for isoelectric focusing (IEF) in the acidic range below pH 5. The majority of compounds described here can serve as primary standards since their pI values were determined by UV-VIS spectrophotometry independently IEF and direct measurement with a pH electrode. Subjected to gel IEF they show narrow and well-observable zones of different colors. Finally, our work resulted in suggestion of a color ladder composed of pI markers covering the pH range from 1.5 to 4.7. 相似文献
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Optimizing dyes for dye-sensitized solar cells 总被引:3,自引:0,他引:3
Robertson N 《Angewandte Chemie (International ed. in English)》2006,45(15):2338-2345
Dye-sensitized solar cells (DSSCs) have emerged as an important cheap photovoltaic technology. Charge separation is initiated at the dye, bound at the interface of an inorganic semiconductor and a hole-transport material. Careful design of the dye can minimize loss mechanisms and improve light harvesting. Mass application of DSSCs is currently limited by manufacturing complexity and long-term stability associated with the liquid redox electrolyte used in the most-efficient cells. In this Minireview, dye design is discussed in the context of novel alternatives to the standard liquid electrolyte. Rapid progress is being made in improving the efficiencies of such solid and quasi-solid DSSCs which promises cheap, efficient, and robust photovoltaic systems. 相似文献
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建立了同时测定染发剂中4,4'-二氨基二苯胺硫酸盐和2,4-二氨基苯酚硫酸盐等6种染料的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法.以水为提取剂进行超声提取,用Waters BEH-C18柱(100 mm×2.1 mm, 1.7 μm)分离,以10 mmol/L的乙酸铵和乙腈为流动相进行梯度洗脱.在电喷雾正离子模式下,采用多反应监测(MRM)模式进行定性和定量分析.6种染料在相应的质量浓度范围内线性关系良好,线性相关系数(R2)均大于0.99,检出限为0.26~4.6 mg/kg,回收率为83.0%~92.2%,相对标准偏差为5.4%~11.2%.方法精密度、准确度、回收率和基质效应均符合染发剂样品测定的要求,用于实际样品测定,结果满意.本方法准确、简便、快速,适用于染发剂中6种染料的分析测定. 相似文献
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Würthner F Stepanenko V Sautter A 《Angewandte Chemie (International ed. in English)》2006,45(12):1939-1942
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Chemically synthesized conducting polyaniline (PANI) was investigated as adsorbent for its possible application in the removal of organic dyes, such as methylene blue (MB) and procion red (PR) from their aqueous solution. PANI adsorbent behaves as a charged surface upon post‐synthesis treatment of the polymer with acid and base. The adsorbent thus treated shows a high selectivity for the removal of dyes in the adsorption process. The Langmuir adsorption isotherm was used to represent the experimental adsorption data. The cationic dye, MB can be preferentially removed by the base‐treated PANI while the anionic dye, PR is predominately removed by the acid‐treated one. These observations were further evidenced from the measurements of molar conductance and pH of the dye solutions employed for adsorption. The finding can be explained considering the electrostatic nature of adsorption coupled with the morphology of the PANI surface thus treated. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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比较研究了在PEG水相和PEG甲苯有机相中辣根过氧化物酶(HRP)的UV-Vis光谱,研究表明,PEG甲苯体系破坏了酶的结构并导致血红素辅基脱落,利用停流光谱仪对HRP与过氧化氢复合物的形成进行研究,结果发现,PEG甲苯体系中复合物Ⅱ的形成比PEG水溶液中复合物Ⅱ形成慢4倍左右,并且在PEG甲苯体系中,复合物Ⅱ很不稳定,导致了酶失活。 相似文献