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1.
本采用装有Jones柱的流动注射系统,研究了钒(Ⅱ)-光泽精体系的化学发光反应。在此基础上建立了痕量钒测定的新方法。方法的检出限3×10^-10g·mL^-1;对于1.0×10^-7g·mL^-1钒标准溶液测定的相对标准偏差为2%(n=11);线性范围1.0×10^-9 ̄9.0×10^-5g·mL^-1,相关系数大于0.9980。该方法已用于水样中痕量钒的测定。对于反应机理,本也进行了探讨。  相似文献   

2.
俞英  洪朝辉 《分析化学》1996,24(4):479-482
水杨醛缩-7-氨基-8-羟基喹啉-5-磺酸(简称S7N8Q5S)在酸性介质中分解,产物呈现荧光,V(Ⅴ)对该反应具有催化作用,本文建立了催化荧光法测定痕量钒的新方法。体系在PH=2的柠檬酸钠-盐酸缓冲溶液中,λex/λem=342/499(nm)。测定V(Ⅴ)的最佳反应条件为0.04%S7N8Q5S5.0mL,5%KBrO35.0mL,缓冲溶液5.0mL,90℃加热5min。V(Ⅴ)含量在12.0  相似文献   

3.
本文采用装有Jones柱的流动注射系统,研究了钒(Ⅱ)-光泽精体系的化学发光反应。在此基础上建立了痕量钒测定的新方法。方法的检出限3×10 ̄(-10)g·mL ̄(-1);对于1.0×10 ̄(-7)g·mL ̄(-1)钒标准溶液测定的相对标准偏差为2%(n=11);线性范围1.0×10 ̄(-9)~9.0×10 ̄(-5)g·mL ̄(-1),相关系数大于0.9980。该方法已用于水样中痕量钒的测定。对于反应机理,本文也进行了探讨。  相似文献   

4.
间硝基氯磺酚与钒(Ⅴ)的显色反应研究及应用   总被引:4,自引:2,他引:2  
研究了间硝基氯磺酚与钒的显色反应。试验表明,以六次甲基四胺为缓冲溶液,钒(Ⅴ)与间硝基氯磺酚能形成稳定的络合物,其最大吸收波长λmax=625nm,表观摩尔吸光系数ε=3.69×104,钒(Ⅴ)与间硝基氯磺酚的络合比为1∶3,钒含量在0~21mg/25L范围内符合比尔定律,用本法测定合金钢中的钒,结果令人满意。  相似文献   

5.
邻氨基酚萃取催化光度法测定痕量钒及其催化反应机理   总被引:12,自引:0,他引:12  
孙登明  阮大文 《分析化学》1998,26(9):1089-1092
研究了在pH3.5的弱酸性介质中,痕量钒(V)能催化溴酸钾氧化邻氨基酚的指示反应,用萃取平衡控制反应时间和水相中邻氨基酚的浓度及反应程度,通过测量424nm下有机相的吸光度,建立了萃取催化光度法测定钒的新方法,方法的线性范围为0.0010~0.30mg/L检出限为1.0×10^-6g/L用于人发,煤和岩石中痕量钒的测定,结果满意,此外,还探讨了反应机理,建立了动力方程。  相似文献   

6.
催化动力学光度法测定痕量钒(Ⅴ)的研究   总被引:4,自引:0,他引:4  
本文研究了在酸性介质中痕量钒(Ⅴ)催化氯酸钾氧化变色酸及抗坏血酸体系的反应和动力学条件,建立了催化动力学光度法测定痕量钒(Ⅴ)的新方法。该方法的检出限为0.08ng/mL V(Ⅴ),线性范围为0~0.3μg/25mL V(Ⅴ)。将该方法用于水样及人发中痕量钒(Ⅴ)测定,结果令人满意。  相似文献   

7.
俞英  洪朝辉 《分析化学》1996,24(10):1147-1151
合成了新型席夫碱类试剂茚三酮缩7-氨基-8-羟基喹啉-5-磺酸,建立了该剂催化荧光测定痕量钒的 新体系,反应在盐酸体系中进行,其λex/λem为325/448(nm),钒(Ⅴ)的量在0-40.0μg/L、40.0-160.0μg/L呈良好线性关系,检测下限为1.7μg/L,方法用于水样痕量钒的测定,结果令人 满意。  相似文献   

8.
氧化藏红T褪色催化荧光法测定痕量钒   总被引:13,自引:3,他引:13  
陈兰化  罗兵 《分析化学》1997,25(6):656-658
研究了在酸性介质中柠檬酸存在下,痕量钒(V)催化溴酸钾氧化藏红T的褪色反应及其动力学条件,建立了催化荧光测定痕量钒的新方法。催化反应在沸水浴中进行8min,为假零级反应,反应的表观活化能力为99.21kJ/mol,反应速度常数为0.12/s;该方法的检出限为2.2×10^-8g/L;线性范围为0.2 ̄2.4μg/L研究了共存离子的影响,用于人发和煤灰中痕量钒的测定,结果令人满意。  相似文献   

9.
催化还原褪色光度法测定痕量铜的研究   总被引:13,自引:0,他引:13  
本文在少量氯化钠存在下的磷酸-磷酸二氢钾缓冲溶液(pH=2.7)中,以铜(Ⅱ)催化次磷酸钠还原罗丹明B褪色为指示反应,建立了痕量铜的动力学光度分析新方法,在沸水浴中加热反应10min,测定的线性范围在0~0.40μg/25mL铜(Ⅱ)回归方程为△A=1.975c+0.003,相关系数为0.9999,以△A=0.01计算得测定下限为0.005μg/25mL。方法应用于铅基合金,纯铅粉和标准镁合金中铜  相似文献   

10.
测定超痕量钒的灵敏指示反应   总被引:4,自引:0,他引:4  
在抗坏血酸存在时,基于在稀硫酸介质中钒(Ⅴ)催化加速溴酸钾氧化中性红的反应,建立了测定超痕量钒的新方法,方法测定范围是0-0.60mg/mL,检出限为7.0*10^-17g/mL,已用于人体血清和河水中超痕量钒的测定。  相似文献   

11.
HEPT类化合物的QSAR研究   总被引:3,自引:0,他引:3  
章文军  许禄 《应用化学》2001,18(9):717-0
为定量结构/活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法(Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物(1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构/活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。  相似文献   

12.
Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum.  相似文献   

13.
通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果.  相似文献   

14.
The content of the fine and ultrafine particles in the raw material results in difficulty of the separation, the loss of the valuable components and ecological contamination. Secondary using of the fine particles is impossible without their granulation. This problem has been solved by the agglomeration-in-liquid method.An agglomeration-in-liquid method is a process to produce agglomerates in a liquid phase from solid particles suspended in the liquid. The surface of solid particles and the binding liquid must be of identical polarity, but the continuous phase must be of the opposite polarity. The water solutions of the surfactant are the binding liquids or the organic liquids.  相似文献   

15.
Similarity of the extrusion curves of non-wetting liquid in a nanoporous medium with different initial fill volume fractions is observed experimentally. The similarity can be explained by the scaling of the interface energy and the self-similarity of the infinite percolation cluster of fluid-filled pores. Understanding the physical processes leading to the observed phenomena is a foundation for the development of high-performance devices for damping and energy storage on the basis of such heterogeneous systems.  相似文献   

16.
The synthesis and liquid crystalline behaviour of the first and second generations of a dendrimeric structure based on poly(propyleneimine)(DAB-dendr(NH2)x) are reported. 4-(4-n-Alkoxybenzoyloxy)salicylaldehydes are used as mesogenic moieties attached at the peripheral amino groups of the dendrimers giving rise to dendromesogens with four and eight mesogenic branches. From these dendromesogens, considered as organic ligands, were prepared six metal-containing dendrimers which incorporate two or four copper atoms in their structures. All the dendrimeric ligands and three of the metal-containing dendrimers exhibit liquid crystalline properties which were studied by optical microscopy, DSC, X-ray diffraction and EPR spectroscopy.  相似文献   

17.
An approximated hardness kernel, which includes the second derivative with respect to the density of the kinetic energy, the electron-electron coulomb repulsion, and the exchange density functionals, has been tested for the calculation of the global hardness. The results obtained for a series of 40 cations and neutral systems and 16 anions represent in most cases an improvement of the results obtained using the HOMO-LUMO gap approach and indicate the viability of this approach to evaluate global hardness. In addition, the relevance of the Fukui function approximation and the role of the three components of the hardness kernel in the evaluation of the global hardness have been analyzed.  相似文献   

18.
A new chromophore, C1 , based on a similar DπA‐structure as in the FTC ‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD ‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.

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20.
用电势阶跃法和旋转圆盘电极法 (RDE)以及SEM和XRD测试手段 ,初步研究了光亮剂对氰化体系中银电沉积行为的影响 .研究表明 ,光亮剂的加入并未导致银电沉积成核机理的改变 ,但显著增强了镀液的微观平整效应 ,并且所得镀层的表观光滑程度明显改善 .XRD测试亦同时表明光亮剂的加入并未改变镀层的择优取向  相似文献   

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