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71.
用金钨杂多酸和耐尔蓝光度法测定纳克量金 总被引:3,自引:2,他引:3
在阿拉伯胶存在下,金与钨酸钠和耐尔蓝(NB)形成离子缔合物,它的最大吸收位于580nm,表观摩尔吸光系数ε值为2.38×10^7L·mol^-1·cm^-1,体系至少稳定24h。金量在0 ̄4.4μg/L范围内服从比尔定律,检测限(3σ)为0.069μg/L(n=12),对4.0μg/L Au(Ⅲ)测定的相对标准偏差为1.9%(n=11),离子缔合物的摩尔比为Au(Ⅲ):NB=1:3。考察了40多种 相似文献
72.
Beatriz Lozano-Torres Dr. Juan F. Blandez Irene Galiana Alba García-Fernández Dr. María Alfonso Prof. María D. Marcos Dr. Mar Orzáez Dr. Félix Sancenón Prof. Ramón Martínez-Máñez 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15264-15268
In vivo detection of cellular senescence is accomplished by using mesoporous silica nanoparticles loaded with the NIR-FDA approved Nile blue (NB) dye and capped with a galactohexasaccharide ( S3 ). NB emission at 672 nm is highly quenched inside S3 , yet a remarkable emission enhancement is observed upon cap hydrolysis in the presence of β-galactosidase and dye release. The efficacy of the probe to detect cellular senescence is tested in vitro in melanoma SK-Mel-103 and breast cancer 4T1 cells and in vivo in palbociclib-treated BALB/cByJ mice bearing breast cancer tumor. 相似文献
73.
74.
Raluca Popescu Diana Costinel Damian Axente 《Isotopes in environmental and health studies》2014,50(4):461-474
One of the most important tributaries of the Danube River in Romania, the Olt River, was characterized in its middle catchment in terms of the isotopic composition using continuous flow–isotope ratio mass spectrometry (CF–IRMS). Throughout a period of 10 months, from November 2010 to August 2011, water samples from the Olt River and its more important tributaries were collected in order to investigate the seasonal and spatial isotope patterns of the basin waters. The results revealed a significant difference between the Olt River and its tributaries, by the fact that the Olt River waters show smaller seasonal variations in the stable isotopic composition and are more depleted in 18O and 2H. The waters present an overall enrichment in heavy isotopes during the warm seasons. 相似文献
75.
Abstract River pollution creates negative externalities to downstream water users. In this paper, we analyze how voluntary joint action of water users can improve pollution abatement when optimal treatment cannot be enforced. We model a transboundary pollution game with a unidirectional pollutant flow. Players are identical except for their location along the river. We find that, surprisingly, the location of coalition members has no impact on coalition stability. Location does, however, affect overall welfare. The more upstream the members of the coalition are, the higher is the overall welfare because the positive externalities of cleaning accrue to a larger number of downstream water users. 相似文献
76.
用钨酸盐和耐尔蓝光度法测定痕量碲 总被引:1,自引:0,他引:1
报告一个简单、灵敏、快速光度测定碲的方法。聚乙烯醇(PVA)存在下,碲与钨酸盐和耐尔蓝(NB)反应形成离子缔合物。离子缔合物的最大吸收峰位于580nm;表观摩尔吸光系数ε值为3.33×10^7L·mol^-1·cm^-1。本方法允许的碲浓度范围为0 ̄6.0μg/L;对4.8μg/L碲(Ⅳ)测定的相对标准偏差为1.3%(n=11);检测限(3σ)为0.011μg/L(n=12)。考察了许多离子的影响 相似文献
77.
A new homogeneous fluoroimmunoassay method based on the use of dynamic long-wavelength fluorescence polarization is presented here for the first time. This methodology, which is applied to the determination of linear alkylbenzenesulfonates (LASs) in water samples, involves the use of a new long-wavelength tracer synthesized from the oxazine dye Nile Blue (NB) via a carbodiimide method. This tracer exhibits fluorescent properties at λex 626 and λem 674 nm. The variation of fluorescence polarization with time is followed using the T-format configuration of the spectrofluorimeter and the analytical parameter used is the initial rate, which is measured in only 0.7 s. The dynamic range of the calibration graph is 0.05-4.7 mg/L, with a detection limit of 0.03 mg/L. The precision, expressed as relative standard deviation was assayed at 0.05 and 1 mg/L, giving values in the range 7.6-9.1%. Other anionic, cationic and non-ionic surfactants were tolerated at much higher concentration levels than that of the analyte. The method has proven its practical usefulness for the analysis of water samples, in which only a solid phase extraction step is necessary. Recoveries ranged from 80.8 to 119.8%, with a mean value of 100.8%. 相似文献
78.
Margarete Mages Stefan Woelfl Mihly
vri Wolf v. Tümpling jun 《Spectrochimica Acta Part B: Atomic Spectroscopy》2003,58(12):2129-2138
A newly developed, portable total reflection X-ray fluorescence (TXRF) spectrometer was tested during a field campaign on Chilean lakes and a German river in January 2002. The field measurements were compared with laboratory measurements carried out on a stationary instrument in the German laboratory. For method validation certified reference material (NIST SRM 1640 Trace elements in natural water) and water samples from different freshwater sources were analyzed with both techniques and evaluated statistically. Based on these preliminary results, it could be concluded that the portable TXRF is a useful technique for the quantitative elemental screening of freshwater samples during field campaigns. Future tests with biological samples (e.g. biofilms and zooplankton), and suspended matter will provide information about the suitability of the portable TXRF for these materials. 相似文献
79.
河流重金属的分布与迁移转化研究进展 总被引:3,自引:0,他引:3
综述了河流重金属的分布和迁移转化研究进展,介绍了该领域的主要研究内容,指出了该领域中存在的问题和发展方向。 相似文献
80.
A semi conducting polymer-modified glassy carbon electrode was fabricated by cyclically sweeping in the potential range of −0.4–1.2 V(vs. SCE) or by electrolyzation at constant potential of 1.4 V in 0.5 M sulfuric acid solution containing 1.0 mM Nile Blue. This redox active polymer could successfully be used for the amperometric determination of hemoglobin. The effect of pH was studied for the polymerization of Nile Blue. It was found that the polymerization did not occur in neutral or basic solutions. The formal potential of this film is −410 mV (pH 7.0) which is more negative than that obtained at the bare electrode in the Nile Blue bulk solution. The electrochemical characteristics of this polymer are discussed. The modified electrode could electrocatalyze the reduction of hemoglobin, and a good linear amperometric response could be obtained over the range of 0.05–7.0 mg/mL (correlation coefficient: 0.985). This modified electrode exhibited good stability and reproducibility for long-term use. 相似文献