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1.
磷钨钒杂多酸-TMBPS电荷转移配合物光度法测定钒 总被引:4,自引:0,他引:4
提出了一种基于形成磷钨钒杂多酸 3,3′,5 ,5′ 四甲基联苯胺 -丙磺酸 (TMBPS)电荷转移配合物的分光光度法测定钒 (Ⅴ )的新方法 ,其最大吸收波长为 45 0nm ,摩尔吸光系数 2 74× 10 4 L·mol-1·cm-1,线性范围 0 0 2~ 1μg·mL-1。采用浮选反萃取分光光度法 ,可提高测定灵敏度 ,其表观摩尔吸光系数增至 3 10×10 5L·mol-1·cm-1。 相似文献
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在酸性条件下 ,N2 可将钴 -硫氰酸铵 -孔雀石绿三元体系浮选于甲苯中 ,利用这一特性本文建立了浮选测钴新光度法。本法灵敏度高 ( ε=1.80× 10 5L·mol-1· cm-1) ,选择性强 ,除 Cu2 +、Zn2 +外其余共存离子基本无干扰 ,精密度可靠 ( RSD=1.89% ) ,测定药品 VB12 中钴的含量 ,结果令人满意 相似文献
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2-(2-喹啉偶氮)-1,5-苯二酚光度法测定铜的研究 总被引:11,自引:2,他引:9
合成了新试剂 2 - ( 2 -喹啉偶氮 ) - 1,5-苯二酚 ( QADHB) ,并研究了其与铜的显色反应 ,在溴化十六烷基三甲胺 ( CTMAB)存在下 ,p H=4 .0邻苯二甲酸氢钾缓冲介质中 ,QADHB与铜反应生成 2∶ 1稳定络合物 ,λmax=540 nm,ε=2 .12× 10 4 L·mol-1·cm-1。铜含量在 0— 30 μg/ 2 5m L内符合比耳定律 ,该方法用于环境样品中铜的测定 ,结果令人满意 相似文献
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2-(2-喹啉偶氮)-4-甲基-1,3-苯二酚光度法测定铜的研究 总被引:2,自引:1,他引:1
合成了新试剂 2 - (2 -喹啉偶氮 ) - 4-甲基 - 1,3-苯二酚 (QAMDHB) ,并研究了其与铜的显色反应 ,在 p H=2 .2的磷酸 -磷酸二氢钾缓冲介质中 ,溴化十六烷基三甲基胺 (CTMAB)存在下 ,QAMDHB与铜反应生成 2∶ 1稳定络合物 ,λmax=5 5 0 nm,ε=4 .84× 10 4L· mol-1· cm-1。铜含量在 0— 2 0μg/ 2 5 m L范围内符合比耳定律 ,方法用于环境水样中铜含量的测定 ,结果令人满意 相似文献
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流动注射在线螯合树脂双柱预富集火焰原子吸收法测定痕量铜、铅、镉和锰 总被引:7,自引:0,他引:7
本文采用流动注射在线阳离子螯合树脂双柱预富集 火焰原子吸收法 ,测定了痕量的铜、铅、镉和锰 ,灵敏度分别提高 33、5 0、37和 2 9倍 ,分析速度为 6 0次·h-1;对于 0 0 5 μg·mL-1Cu2 +、0 2 5 μg·mL-1Pb2 +、0 0 2 5 μg·mL-1Cd2 +和 0 0 5 μg·mL-1Mn2 +溶液 ,测定的相对标准偏差分别为 2 2 1%、3 2 4%、1 93%和3 6 6 % (n =11) ;对标准物质 (人发、小麦及猪肝 )进行了测定 ,结果与标准值相符。此法应用于饮用水和环境水样中铜、铅、镉和锰的测定 ,获得了满意的结果。 相似文献
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本文研究了新试剂 2 -羧基 - 5 -硝基苯基重氮氨基 - 4 -苯基 - 2 -噻唑 ( CNPDAPT)在 Triton X- 1 0 0的存在下 ,与铜显色反应的适宜条件。结果表明在 p H1 0 .0的 Na2 B4O7- Na OH缓冲介质中 ,铜与试剂形成 1∶ 1红色配合物 ,其最大吸收波长位于 5 1 5 nm,表观摩尔吸光系数 ε=4.5 9× 1 0 4 L· mol- 1· cm- 1 ,铜量在0 - 2 0 μg/ 2 5 m L范围内遵守比耳定律。方法用于水样中微量铜的测定 ,结果满意。 相似文献
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ABSTRACT In this work, a novel displacement solidified floating organic drop microextraction (D-SFODME) technique was developed and coupled with electrothermal atomic absorption spectrometry (ETAAS) for the determination of trace silver in water samples without need of any masking agents. The method involved the formation of copper diethyldithiocarbamate (Cu–DDTC), extracted from the resultant Cu–DDTC with SFODME procedure using 1-undecanol. Then, the solidified floating organic drop was transferred into a sample solution containing silver ion, and another SFODME procedure was carried out. Trace Ag+ was selectively preconcentrated using 1-undecanol through a displacement reaction between Ag+ and the preconcentrated Cu-DDTC and the floating organic drop was diluted by ethanol for ETAAS detection. Interferences from coexisting heavy metal ions with lower stability of their DDTC complexes relative to Cu-DDTC were minimized. Under the optimal conditions, the limit of detection was 4.7 ng L?1 (3σ) for silver with a sample volume of 5.0 mL, and an enrichment factor of 250 was achieved. The relative standard deviation under optimum conditions is 3.6% (n = 7). The proposed method was successfully applied to determine trace silver in some environmental samples with satisfactory results. 相似文献
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In a suitable pH buffer solutions, sodium diethyldithiocarbamate (DDTC) reacts with some divalence metal ions M(II) to form
(M–DDTC)
n
chelate complex nanoparticles, which exhibit different luminescence properties. There is a strongest luminescence peak at
470 nm for the Co(II)–DDTC system, three peaks at 330, 470, and 630 nm for the Cu(II)–DDTC system, three peaks at 420, 470,
and 630 nm for the Cd(II)–DDTC system, four peaks at 350, 400, 435, and 470 nm for the Ni(II)–DDTC system, two peaks at 408
and 470 nm for the Pb(II)–DDTC system, two peaks at 415 and 470 nm for the Fe(II)–DDTC system. The different luminescence
properties of (M–DDTC)
n
chelate complex nanoparticles was explained. Under the optimal conditions, the luminescence intensity of (Co–DDTC)
n
chelate complex nanoparticles at 470 nm (F
470 nm) is linear to Co(II) concentration in the range of 0.012–1.44 μg/mL. The detection limit is 0.0023 μg/mL. A novel luminescence method has been proposed for the determination of cobalt in Vitamin B12 samples, with satisfactory results. 相似文献
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催化动力学褪色光度法测定痕量铜(Ⅱ)的研究 总被引:18,自引:0,他引:18
研究了在盐酸介质中 ,铜 (Ⅱ )催化过氧化氢氧化孔雀绿褪色反应的适宜条件与影响因素 ,建立了催化动力学光度法测定痕量铜的新方法。该方法是用固定时间法在 6 15nm波长处监测催化反应。方法的线性范围为 0~ 2 2 μg·L- 1 ,检出限为 1 92× 10 - 9g·mL- 1 ,该催化反应对铜 (Ⅱ )为一级反应 ,表观活化能为12 2 3kJ·mol- 1 ,表观反应速率常数为 7 70× 10 - 4s- 1 。因为Fe3 干扰Cu(Ⅱ )的测定 ,用PO3-4与Fe3 生成稳定的 [Fe(PO4 ) 2 ]3- 络合物 ,可掩蔽Fe3 。方法相对标准偏差为 1 16 % ,标准加入回收率为 98 3%~10 0 3%。该方法用于水样品、茶叶样品、奶粉样品以及苹果样品中铜的测定 ,获满意结果 相似文献
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研究了以铜(Ⅱ)离子作为模板离子,合成了铜(Ⅱ)离子印迹聚合物并将其做成固相萃取柱,直接安装在流动注射系统上,对样品中的铜(Ⅱ)离子进行在线分离富集;经H2SO4+乙醇混合溶液洗脱液在线洗脱后.在H2SO4介质中,铜(Ⅱ)离子催化高锰酸钾氧化桑色素发生化学发光反应.据此建立了灵敏简单流动注射化学发光法测定铜的新方法.在... 相似文献
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张淑芳 《光谱学与光谱分析》2006,26(3):535-538
提出了运用吸光度比值-导数光谱法同时测定Cr(Ⅲ)与Cu(Ⅱ)含量的新方法。在pH 5.7的HAc-NaAc的缓冲溶液中,Cr3+,Cu2+与铬天青S(CAS)和溴化十六烷基三甲胺(CTMAB)可分别形成蓝色三元络合物。其摩尔吸光系数分别为2.52×105 L·mol-1·cm-1和1.01×105 L·mol-1·cm-1。Cu2+和Cr3+的浓度分别在0.08~1.2 μg·mL-1和0.05~0.52 μg·mL-1范围内符合比尔定律,其检测限分别为0.014和0.013 μg·mL-1。此方法应用于环境水中Cr(Ⅲ),Cu(Ⅱ)的同时测定,取得了满意的结果。 相似文献
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以轻质溶剂辛醇为萃取剂,建立了分散液液微萃取-石墨炉原子吸收光谱分析法(LDS-DLLME-GFAAS),并应用于生活用水中痕量Pb及Cd的测定。在分散液液微萃取(DLLME)中,以二乙基二硫代氨基甲酸盐(DDTC)为螯合剂,用微量注射器将辛醇和甲醇的混合溶液快速注入到样品溶液中发生雾化分散现象,Pb2+和Cd2+与DDTC的络合物被萃取到辛醇微滴中。离心分离后,以GFAAS测定萃取至上层辛醇相中的分析物。实验考察了萃取剂种类和体积、分散剂种类和体积、pH、DDTC浓度、萃取时间等影响萃取效率的实验参数。在最优实验条件下,Pb和Cd的检出限分别为0.15和0.03 μg·L-1,富集倍数分别为87和48,具有良好的线性和精密度。该分析方法优势在于操作简便,快速,低成本,高富集倍数,萃取剂用量少,已成功应用于自来水、饮用水和南湖水中痕量Pb和Cd的检测。 相似文献
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R. V. Gulyaev N. A. Kryuchkova L. N. Mazalov A. I. Boronin T. V. Basova V. A. Plyashkevich 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(1):48-56
The charged states of atoms in unsubstituted copper(II) phthalocyanine (CuPcH16) and hexade-cafluorinated copper(II) phthalocyanine (CuPcF16) complexes and in thin films of them deposited on silicon substrates by vacuum thermal evaporation are investigated by X-ray
photoelectron spectroscopy (XPS). The C(1s), N(1s), Cu(2p) core level energies and the charged states of atoms in the studied complexes are calculated using the DFT method. The performed
experimental study and theoretical calculations show that the introduction of electron acceptor substituents into benzene
rings mostly affects the atoms of benzene rings and insignificantly affects the charge state of nitrogen atoms in the pyrrole
ring. 相似文献
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A comparison between EPR spectra of rigidly linked dicopper porphyrin dimers and those of the corresponding monocopper dimers (copper porphyrin-free base porphyrin dimers) in fluid solution reveals a very weak exchange interaction between the two copper spins. In these dimers, two porphyrin moieties are linked via an aromatic spacer such as benzene, naphthalene or phenanthrene in a gable-type geometry, with a distance of 10–13 Å. Although essentially all the spectra from the monocopper dimers are the same, exhibiting hyperfine (hf) structure due to the copper and nitrogen nuclei, the EPR spectral patterns of the dicopper dimers depend on the spacer molecule. Differences in hf patterns among the dicopper porphyrin dimers are ascribed to isotropic spin—spin coupling, i.e., exchange coupling between the two copper spins. This is because the anisotropic dipole—dipole interaction is averaged out due to random tumbling of the solute molecules in fluid solution. From the line shape analysis, the absolute value of the exchange interaction (|J|) is found to be 4 × 10?4 cm?1 ≦|J| < 3 × 10?3 cm?1 for the benzene linked dicopper dimer (Cu—Bz—Cu) whereas |J| ~ 1 × 10?4cm?1 for the other two dimers (Cu—Np—Cu and Cu—Pn—Cu). These values are comparable with or much smaller than the dipole—dipole coupling, which is estimated as about 1–3 × 10?3 cm?1 from the centre-to-centre distance. Since Cu—Bz—Cu shows a significantly larger |J| than Cu—Pn—Cu, despite a slightly longer centre-to-centre distance, and since no correlation could be obtained between |J| and the separation of the two copper atoms, it is likely that the interaction via spacer molecules is dominant between the two halves. 相似文献