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1.
Abstract

A method for the spectrophotometric determination of cobalt (II) by complexation with di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution is described. Cobalt (II) forms a 1:2 complex with DPKBH. The complex has maximum absorbance at 370 nm. Beer's law is obeyed over the range 0.1 – 2.8 μg.ml?1. The effect of pH, effect of excess reagent, stability of the complex and the tolerance limit of many metal ions have been reported. The method is applied to the determination of cobalt in different alloys containing other metals ions.  相似文献   

2.
系数倍率双波长标准加入法同时测定铜和铁的研究   总被引:3,自引:0,他引:3  
本文报道了一种同时测定铁和铜的新方法。在含有乳化剂OP的弱酸性介质中,显色剂1-(2-吡啶偶氮)-2-萘酚与铜,铁形成红色配合物,其最大吸收波长为560nm。本法选择560nm为测定波长,600nm为参比波长,按系数倍率双波长标准加入法原理处理数据,实现了铜和铁的同时测定,并应用该法直接测定了铝合金中铜和铁的含量,结果满意。  相似文献   

3.
Abstract

Nitrogen-containing heterocyclic hydrazones have been used as analytical reagents, mainly to metallic ion spectrophotometric determinations in natural water samples. Using the reagent di-2-pyridil ketone benzoilhydrazone (DPKBH) we have developed a spectrophotometric method for the determination of Ni(II) in samples of several sources. DPKBH was used in excess in order to coordinate Ni(II) and the highest sensitivity was obtained in 50% v/v ethanol solutions when ammonium acetate buffer was added to maintain pH?6.

Analysis for Ni(II) in natural water is frequently performed by EAAS following preconcentration involving solvent extraction. While these methods are sensitive, they also require relatively expensive instrumentation and are generally time-consuming. In contrast, the advantages of the proposed method are the use of simple instrumentation and the possibility of its application in the field. The method is fast, shows high sensitivity, good precision and several samples can be prepared and measured until 10 hours later .

The best order for the addition of reagents, stability of the complex, effect of the reagents excess and foreign ions besides composition of the complex are here reported. A linear behavior was observed between absorbance and nickel concentration. The favorable range is 8.50×10?7 to 1.72×10?5 mol.L?1. The correlation coefficient is 0.997. The intercept of the linear curve is 3.55×10?3 and the slope is 4.00×104cm?1.moI?1.L. The standard error of the intercept and slope is 3.73×10?3 and 4.48×10?4, respectively.  相似文献   

4.
本文提出了胡椒基荧光酮 (PIF)硅胶H相反射散射光度法测定铁的新方法。在溴化十六烷基三甲基铵的存在下 ,PIF与铁 (Ⅲ )形成稳定的蓝色配合物并且能被硅胶H吸附 ,其最大反射散射吸收波长位于 6 4 0nm ,铁 (Ⅲ )的浓度在 0~ 2 5ng·mL- 1 范围内呈线性关系 ,方法用于氧化镁中微量铁的测定 ,结果满意。  相似文献   

5.
研究新合成的水溶性光度试剂N-壬基-N‘-(氨基对苯磺酸钠)硫脲与钯的显色反应。结果表明,在pH5.8-6.6的HAc-NaAc缓冲体系中,Pd^2+与NTP形成1:4的黄色水溶性配合后物,CTMAB对反应有明显的增敏作用,配合物的最大吸收波长位于297.6nm,表面摩尔吸光系数ε297.6=1.27×10^5L.mol^-1cm^-1,钯含量在2-11.2μg/25mL范围内服从比尔定律,50种  相似文献   

6.
The mono(pyridine-N-oxide) analog of the H4dota macrocylic ligand, H3do3a-pyNO, is capable of forming thermodynamically stable and kinetically inert Ln(III) complexes. Its Eu(III) and Tb(III) complexes display a strong long-lived fluorescence as a result of the antenna effect of the pyridine-N-oxide fluorophore in the reagent. It is shown that H3do3a-pyNO can be used as a fluorogenic reagent for the determination of Eu(III) and Tb(III) at pH 6.5 and cL=1 mM. At an excitation wavelength of 286 nm, the emission maxima are 615 nm (Eu(III)-complex), and 547 nm (Tb(III)complex). Detection limits are at concentrations around 1.0 μM and linearity of the method spans over 2 orders of magnitude. The method was applied to artificial and real samples (spiked mineral waters, extracts from cathode ray tube luminophore dust) and gave satisfactory results. The method is simple, rapid, and hardly interfered by other metal ions.  相似文献   

7.
建立了流动注射(FI)编结反应器(KR)在线预富集与火焰原子吸收光谱(FAAS)联用非分离状态下测定铁的价态的新方法。进样流速6.0 mL.min-1;进样时间60s,测定0.04 mg.L-1的Fe(Ⅲ)和Fe(Ⅱ),Fe(Ⅲ)和Fe(Ⅱ)的浓集系数(EF)分别为41和9;检出限分别为2.5和14.3μg.L-1;相对标准偏差(RSD,n=11)分别为2.3%和3.1%。以0.1‰φ的三乙醇胺为掩蔽剂,Fe(Ⅲ)和Fe(Ⅱ)在水样中的回收率分别为97%~101%和96%~100%。  相似文献   

8.
析相光度法测定铁(Ⅲ)的研究   总被引:2,自引:0,他引:2  
本研究了铁(Ⅲ)-PEG(聚乙二醇-2000)-铬锖R-Na2SO4体系的上光度法并应用于测定Fe(Ⅲ)。最适酸并为4.5 ̄6.5(NaAc-HAc)缓冲溶液,其络合物的最大吸收位于560nm,表观摩尔吸光系数为5.36×10^4L·mol^-1·cm^-1,Fe(Ⅲ)浓度在0 ̄4μg范围内服从比尔定律,铁与铬菁R形成组成为1:2的稳定络合物。该方法用于蔡叶中铁的测定,获得了满意的结果。  相似文献   

9.
The infrared and electronic spectra of twelve amphiphilic complexes of N-hexadecyl-8-hydroxy-2-quinoline carboxamide (HL) have been investigated. In IR spectra a linear relationship between the v (C-O) frequency in C-O-M bond of the complexes and the relative atomic weight of the central metal ions and a linear relationship between the v (C-O) frequency and the ionization potential of the central metal (M →M2+(g)+2e) were obtained. These complexes appeared to fall into two groups. One is the complexes of closed-shell metal ions such as Ca(II), Mg(II), Zn(II), Cd(II), Al(III), La(III) and Gd(III) ion, the other is the complexes of transitional metal ions such as Mn(II), Co(II), Ni(II) and Cu(II) ion. All these complexes can form stable monolayer and can be deposited as uniform LB films.  相似文献   

10.
PAR-吖啶黄能量转移荧光猝灭法测定痕量铁(Ⅱ)的研究   总被引:4,自引:2,他引:2  
对 4 (2 吡啶偶氮 ) 间苯二酚 (PAR)与吖啶黄间荧光能量转移进行了探讨 ,研究了其能量转移的最佳条件 ,并应用该体系测定痕量铁 (Ⅱ ) ,由此建立了能量转移荧光测定痕量铁的新方法。在λex/em =46 5nm/5 0 5nm ,十二烷基硫酸钠 (SDS)作用下 ,pH =9 2时 ,吖啶黄与PAR 铁 (Ⅱ )络合物间能发生有效能量转移 ,使吖啶黄的荧光猝灭。铁的量在 0~ 10 μg·L-1范围内呈良好的线性关系。最低检出限 0 0 6 μg·L-1。该方法用于水样、发样中痕量铁的测定 ,结果满意。  相似文献   

11.
Iron(III)-doped titania nanoparticles were prepared by modified sol-gel method using titanium (IV) butoxide and inorganic precursor iron(III) nitrate nonahydrate. Spectroscopic measurements show the onset of the band-gap transition to be red-shifted (~λ = 475 nm) to the visible region with increasing iron(III) ion content. Characterizations were preformed by X-ray diffractometry, electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Photocatalysis experiments were performed with dye pollutant sulforhodamine-B in aqueous environment. Direct photocatalytic effect was observed in the dye degradation experiments when irradiated with visible light into the band gap of the iron(III)-doped titania.  相似文献   

12.
研究了三种新型不同链长尾式卟啉 -吡啶季铵盐与Cu2 的显色反应条件 ,其络合物最大吸收波长分别为 4 13nm(Ⅰ ) ,(Ⅱ ) ;4 14nm(Ⅲ )。在相同条件下 ,试剂最大吸收波长分别为 4 4 3 5nm(Ⅰ ) ;4 4 4nm(Ⅱ ) ;4 4 6nm(Ⅲ )。对比度大约 30nm。试剂与铜络合比均为 1∶1,表观摩尔吸光系数为 (Ⅰ ) 3 4× 10 5,(Ⅱ )2 9× 10 5;(Ⅲ ) 2 5× 10 5L·mol-1·cm-1,铜含量分别在 (Ⅰ ) 0~ 0 5 μg·( 10mL) -1;(Ⅱ ) 0~ 0 6 μg·( 10mL) -1;(Ⅲ ) 0~ 1 0 μg·( 10mL) -1内符合比尔定律 ,可用于痕量铜的测定。  相似文献   

13.
研究了在pH =5 5的弱酸性介质中 ,利用Fe(Ⅲ ) ,Mo(Ⅵ )对H2 O2 氧化邻氨基酚催化反应速率不同 ,用萃取平衡控制反应时间和水相中邻氨基酚的浓度及催化反应进行的程度 ,通过测量 4 2 4nm下有机相的吸光度 ,建立了萃取催化光度法同时测定铁和钼的新方法。同时测定铁和钼的线性范围分别为 0 0 10~ 0 0 30 μg·mL- 1 和 0 5 0~ 2 0 μg·mL- 1 。用于大豆中铁和钼的测定 ,结果满意。  相似文献   

14.
Abstract

In order to have more information about the thermodynamic properties of the complexes formed by Cobalt(II) and DPKBH (di-2-pyridyl ketone benzoylhydrazone) and for the development of speciation methods for cobalt, the respective stepwise formation constants were determined in ethanolic solution 50% (V/V), at pH 5.3 and 25.0°C. The spectrophotometric method of corresponding solutions was used and the following overall formation constants were obtained: β1 = 5.305 × 106 M?1 and β2 = 8.476 × 1010 M?2. The molar absorptivities of the 1:1 (ε1) and 1:2 (ε2) complexes (Co(II):DPKBH) were determined to be 4.475 × 10 and 2.994 × 10 (M?1cm?1), respectively. The calculated distribution diagram shows the percentage of the species at equilibrium as a function of the free DPKBH concentration.  相似文献   

15.
多波长线性回归分光光度法同时测定油中的铁、钴、镍   总被引:7,自引:0,他引:7  
本文提出一种同时测定铁,钴,镍的新方法,即多波长线性回归分光光度法,利用铁与5-Br-PADAP形成的络合物在750nm处吸收峰不受钴,镍干扰的特点,在750nm处于工作曲线法测定铁的含量,对于钴,镍在550-600nm内采用多波长线性回归法测定。应用于合成样及油样中铁,钴,镍含量的测定,结果令人满意,回收率为95.7% ̄104.3%,相对标准偏差为1.4% ̄3.8%。  相似文献   

16.
一阶导数光谱法同时测定石英砂中铁和铝的研究   总被引:7,自引:1,他引:6  
研究了在pH=6.0的HAc-NaAc缓冲体系中,Al(Ⅲ)和Fe(Ⅲ)分别与乙二醇二乙醚二氨基四乙酸(EGTA),邻苯三酚红(PR),溴化十六烷基吡啶(CPB)形成的四元络合物的性质,利用一阶导数光谱法对微量铁和铝进行了同时测定,测定的变异系数分别为4.5%和1.1%,加标回收率分别为93-98%和95-102%,方法可用于石英砂中微量铁和铝的测定。  相似文献   

17.
本文在邻二氮菲光度法的基础上,引入导数光谱峰面积技术,对微量铁进行定量测定,该方法避免了有关离子的干扰,提高了准确度,用之于面粉、奶粉和肝等食品样品分析,所获结果令人满意。  相似文献   

18.
利用二甲酚橙作萃取剂 ,在吐温 80 (NH4 ) 2 SO4 二甲酚橙 (XO)固 液萃取体系中 ,研究了萃取相 (固相 )中金属离子络合物吸收光谱 ,与XO光谱比较 ,Cu(Ⅱ ) ,U(Ⅵ ) ,Ce(Ⅳ )离子吸光度增大 ,最大吸收波长红移 2 0~ 30nm ;La(Ⅲ )离子几乎未变。同时探讨了该体系中不同酸度、不同盐用量、不同萃取剂用量、不同类型表面活性剂 ,对Cu(Ⅱ ) ,La(Ⅲ ) ,U(Ⅵ ) ,Ce(Ⅳ )离子的萃取率的影响 ,在pH 6 0的酸度下 ,实现了La(Ⅲ )与U(Ⅵ )之间的萃取分离。  相似文献   

19.
The preparation of ternary iron(II) complexes [Fe(CN)2(LL)2] and [Fe(CN)4(LL)]2-, where LL = a Schiff base derived from 2-acetyl pyridine and a long chain amine 1-Me(CH2)nNH2 (n = 11, 15, 17), is described. These complexes exhibit strong solvatochromism and can thus be used to probe solvation in organised aqueous media, as in ternary water - Aerosol OT- hexanol mixtures. They also have a dramatic effect on the micellisation behaviour of the uncharged surfactant Triton X-100.  相似文献   

20.
Complexation and photophysical properties of complexes of lanthanide ions, Ln(III), with diethyl(phthalimidomethyl)phosphonate ligand, DPIP, were studied. Interactions between Ln(III) and DPIP were investigated using Nd(III) absorption and Eu(III) and Tb(III) luminescence (emission and excitation) spectra, recorded in acetonitrile solution containing different counter ions (NO3-, Cl- and ClO4-). Results of the absorption spectroscopy have shown that counter ions play a significant role in the complexation of Ln(III)/DPIP complexes. Studies of luminescence spectra of Eu(III) and Tb(III) ions proved that the formation of Ln(III)/DPIP complexes of stoichiometry Ln:L=1:3 is preferred in solution. Based on the results of elemental analysis, Nd(III) absorption spectra and IR and NMR data, it was shown that the DPIP ligand binds Ln(III) ions via oxygen from phosphoryl group, forming complexes of a general formula Ln(DPIP)3(NO3)3·H2O, in which the NO3- ions are coordinated with the metal ion as bidentate ligands. Luminescent properties and energy transfer, from the ligand to Ln(III) ions in the complexes formed, were studied based on the emission and excitation spectra of Eu(III) and Tb(III). Their luminescent lifetimes and emission quantum yields were also measured.  相似文献   

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