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以新型环保多齿螯合剂——亚氨基二琥珀酸(IDS)为配体,在优化条件下,合成了IDS-Silica固定相。用电位滴定法测定了固定相上IDS的键合量。考察了IDS-Silica柱的色谱特性以及金属螯合特性。使用制备柱成功地分离了标准蛋白质混合物,该制备柱展现出了典型的阳离子交换特性。用电感耦合等离子体原子发射光谱法考察了金属离子在IDS-Silica固定相上的键合特性。结果表明,金属离子在IDS-Silica固定相上键合量的变化规律与它们同该固定相螯合的强弱顺序一致。通过比较金属Cu~(2+)在4种不同氨羧类配体硅胶柱上的键合量,发现IDS对金属离子具有强的螯合能力。IDS对金属离子的强螯合特性为其今后作为固定金属亲和色谱填料奠定了基础,为缓解亲和柱在使用过程中固定金属离子的流失提供了一种有效的解决方法。 相似文献
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(一)前言在若干种离子的混合溶液中,欲不经分离而进行个别离子的氨羧络合滴定,必须控制滴定条件。根据作者提出的酸效应公式,可以计算在混合溶液中,控制酸度滴定个别离子的最高和最低酸度范围。但是,对于氨羧络合物的稳定性相近的一些离子(例如△pK<5时),欲不经分离而进行选择滴定,单 相似文献
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利用密度泛函方法, 基于靛蓝的电子结构, 对其锌离子络合物的可能结构及其光学性质进行了系列理论预测和分析. 计算结果表明, 异构体的不同轨道电子跃迁机理使得靛蓝异构体具有不同的吸收光谱. 理论上计算得到的4种靛蓝锌离子稳定络合物中, 有3种是以顺式靛蓝为配体, 可以预测络合反应中同时应该伴有靛蓝的异构过程, 由络合物的光化学特征可以预测, 靛蓝作为有机染料指示剂在金属离子标定的反应过程中可能生成不同的靛蓝金属络合物分子. 相似文献
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金属离子在液相氧化中的催化作用 Ⅰ.乙苯液相氧化中s-,d-,f-类金属离子的催化作用 总被引:1,自引:0,他引:1
本文广泛研究了s-,d-,f-类金属离子在乙苯液相氧化中的催化性能。发现金属膏子在液相氯化反应中的催化活性变化规律和其在多相催化氧化反应中相似,即与金属氯的成键能力有关;对中间产物乙苯过氧化氢的选择性则取决于离子的氯化还原电位。f-类元素的铈离子具有独特的催化性能,其催化活性与d-类金属离子相似,而其对乙苯过氧化氢的选择性则接近于s-类金属离子。根据实验结果,提出了络合—链锁反应机理:金属离子首先和分子氧络台生成氧的活性络合物,然后和反应物分子相互作用,生成自由基并按链锁反应机理继续进行。 相似文献
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稀土-氨基多羧酸类配合物的分子结构及配位规律的研究 总被引:9,自引:0,他引:9
报道了稀土金属离子与一系列氨基多羧酸类配体形成配合物的分子结构和晶体结构. 讨论了稀土金属离子与氨基多羧酸类配体的配位规律, 证明了稀土金属离子像其他过渡金属离子一样, 与氨基多羧酸配体形成配合物的配位数和配位结构取决于稀土金属离子的离子半径, 电子结构和氧化态以及氨基多羧酸类配体的形状. 氨基多羧酸类配体是指氨基三乙酸(=nta), 乙二胺四乙酸(=edta), 反式-1,2-环己二胺四乙酸(= Cydta), 二乙三胺五乙酸(= dtpa)和三乙四胺六乙酸(=ttha). 相似文献
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A method of determination of Co, Cu, Pb and Ni in nanogram quantities from aragonite is presented. Flotation and extraction of Co, Cu, Pb and Ni is suggested as methods for elimination matrix interferences of calcium. The method of flotation is performed by iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)(3), as a colloid precipitate collector. The liquid-liquid extraction of Co, Cu, Pb and Ni is carried out by sodium diethyldithiocarbamate, NaDDTC, as complexing reagent into methylisobutyl ketone, MIBK. The electrothermal atomic absorption spectrometry (ETAAS) is used for determination of analytes. The detection limits of ETAAS followed by flotation are: 7.8 ng.g(-1) for Co, 17.1 ng.g(-1) for Cu, 7.2 ng.g(-1) for Pb and 9.0 mug.g(-1) for Ni. The detection limits of ETAAS followed by extraction are found to be: 12.0 ng.g(-1) for Co, 51.0 ng.g(-1) for Cu, 24.0 ng.g(-1) for Pb and 21.0 ng.g(-1) for Ni. 相似文献
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Magnetically driven separation technology has received considerable attention in recent decade for its great potential application. In this study, we investigate the application of silica-modified magnetite nanoparticles (NPs) coated with a cationic surfactant as adsorbent for microextraction and determination of trace amounts of Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) from environmental water samples. The synthesized silica-coated NPs in combination with cetylpyridinium bromide have the ability to adsolubilize the metal ions after complexation with 8-hydroxyquinoline. The NPs bearing the target metals are easily separated from the aqueous solution by applying an external magnetic field and the complexed metals were desorbed using acidic methanol. The desorbed analytes are introduced into the graphite furnace of an atomic absorption spectrometer. The effect of pH, complexing agent, amount of cetylpyridinium bromide, microextraction time, desorption conditions, ionic strength on extraction efficiency of the metal ions are investigated and optimized. Under the optimized conditions, the detection limits for Cu(II), Ni(II), Co(II), Cd(II), Pb(II) and Mn(II) are 4.7, 9.1, 9.5, 2.3, 7.4 and 15.3 ng L−1, respectively and the relative standard deviations (n = 6) are less than 3.6%. The accuracy of the method was evaluated by recovery measurements on the spiked samples and good recoveries (93-113%) with low RSDs were achieved. 相似文献
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A simple preconcentration method is described for the determination of Cu, Mn, Co, Cd, Pb, Ni and Cr in water samples by flame AAS. Trace metal ions in water were sorbed as pyrocatechol violet complexes on activated carbon column at the pH range of 4–8, then eluted with 1 M HNO3 in acetone. The effect of major cations and anions of the natural water samples on the sorption of metal ions has been also investigated. The concentration of the metal ions detected after preconcentration was in agreement with the added amount. The present method was found to be applicable to the preconcentration of Cu, Mn, Co, Cd, Pb, Ni and Cr in natural water samples with good results such as R.S.D. from 3 to 8% (N=10) and detection limits under 70 ng l−1. 相似文献
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The mixture of metal ions [Bi(III), Fe(III), Fe(II), Cu(II), Zn(II), Ni(II), Co(II), Pb(II), Cd(II), Mn(II)] were separated in the bonded-phase strong cation exchange column (Vydac-401 SA) and monitored at 540 nm after a postcolumn reaction with 4-(2-pyridylazo)-resorcinol (PAR). Citrate, tartrate, lactate and α-hydroxyisobutyrate buffer were used as eluent and it has been found that the elution order of some metal ions were changed with different eluents. The detection limits and the calibration curves of metal ions were also studied. 相似文献
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Georg Schwedt und Peter Schneider 《Fresenius' Journal of Analytical Chemistry》1986,325(1):116-120
Zusammenfassung Co, Ni und Cu werden nach prä-chromatographischer Derivatisierung als N-Methyl-N-2-sulfoethyl-dithiocarbamate (DTC) mittels eines Ionenpaar-Reversedphase-Systems getrennt. Die Metalle lassen sich bis zu Nachweisgrenzen von etwa 1 ng in der Säule bei 400 nm Detektionswellenlänge quantitativ analysieren. Bei hohen Eisenüberschüssen ist die post-chromatographische Derivatisierung mit dem ebenfalls wasserlöslichen 1-Carboxy-N,N-cyclotetramethylen-DTC in Kombination der Ionen-Chromatographie der Metallionen besser geeignet. Neben Cu, Co und Ni lassen sich auch Fe und Pb trennen sowie bei 320 nm optimal detektieren. Die Nachweisgrenzen für Co und Ni betragen 0,5 bzw. 0,2 ng absolut. Die Anwendbarkeit dieses Analysensystems für Co- und Ni-Spurenanalysen in Hülsenfrüchten wird gezeigt.
Herrn Prof. Dr. H. Hartkamp zum 60. Geburtstag gewidmet 相似文献
Pre- and post-chromatographic derivatization by water soluble dithiocarbamates for HPLC analysis of metal ions
Summary Cobalt, nickel and copper are separated by ionpair reversed-phase chromatography after pre-chromatographic derivatization to N-methyl-N-2-sulfoethyl-dithiocarbamates (DTC). The metals can be quantitatively determined with detection limits of 1 ng in the column at a detection wavelength of 400 nm. In the presence of a high excess of iron the post-chromatographic derivatization with 1-carboxy-N,N-cyclotetramethylene-DTC in combination with the ion-chromatography of the metal ions is more suitable. Besides cobalt, nickel and copper, iron and lead can also be separated and optimally detected at 320 nm. The detection limits in the column are 0.5 ng for cobalt and 0.2 ng for nickel. The applicability of this system has been shown for the trace analysis of cobalt and nickel in legumes.
Herrn Prof. Dr. H. Hartkamp zum 60. Geburtstag gewidmet 相似文献
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反相高效液相色谱法同时测定镉、铅、铜和锌 总被引:12,自引:1,他引:11
研究了meso-四(对羟基苯基)卟啉为柱前衍生化试剂与Cd2+,Pb2+,Cu2+和Zn2+离子的配合反应条件及配合物在C18色谱柱上的分离条件,建立了反相高效液相色谱快速分离光度检测Cd2+,Pb2+,Cu2+和Zn2+的新方法。配合物和试剂在15 min内出峰完毕。4种离子的检出限为: Cd2+0.02 ng,Pb2+0.02 ng, Cu2+0.02 ng,Zn2+0.12 ng;线性范围为:Cd2+0.8 μg/L~150 μg/L,Pb2+0.8 μg/L~300 μg/L,Cu2+0.8 μg/L~500 μg/L,Zn2+5.0 μg/L~1 000 μg/L;方法的日内相对标准偏差为:2.8%~4.8%,测定低、中、高3个浓度的日间相对标准偏差为3.7%~9.7%。 相似文献
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Deleterious trace impurities like Mn, Fe, Co, Ni, Zn, Bi and Pb in oxygen-free electronic copper (OFEC) were separated and determined by dynamic coating ion-interaction chromatography (IIC) with spectrophotometric detection using pre-column reaction methods. 4-(2-Thiazolylazo)resorcinol (TAR) was used as pre-column chelating agent. The requirements for sample preparation and the conditions for pre-column chelation reaction are discussed. The optimum conditions for the sensitive detection of these trace metal ions after ion-chromatographic separation are set. The ph of the chelating medium and the eluent, the concentration of TAR and the composition of the eluent were investigated. The detection limits achieved were 2.0, 2.8, 0.6, 0.8, 1.2, 2.6 and 3.0 ng for Mn, Fe, Co, Ni, Zn, Bi and Pb, respectively. The results obtained by IIC methods compare well with those of graphite furnace atomic-absorption spectrometry and the certified values of Mur Bundy Hamil (MBH Analytical Ltd, U.K.). 相似文献
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以4-(2-苯并噻唑偶氮)间苯二酚作柱前衍生试剂,CLC-C8为固定相,甲醇-水(68:32,V/V)含2×10-3mol/LTBA·Br为流动相,在波长550nm处光度检测.可分离和测定Cu(Ⅱ)、V(Ⅴ)、Co(Ⅱ)、Fe(Ⅲ)和Ni(Ⅱ)。检出限分别为2.5×10-1ngCu、9×10-2ngV、1.3×10-1ngCo、1.4×10-1ng Fe和2.9×10-1ng Ni.方法应用于保证纯及分析纯盐酸试样分析,获得满意的结果. 相似文献
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A highly sensitive, non-selective trace metal detector based on chemiluminescence has been developed. The metals, separated by simple ion-exchange chromatography, bring about the displacement of cobalt from a Co-EDTA post-column reagent. The liberated cobalt is then detected by the luminol-peroxide chemiluminescence reaction using a modified spectrofluorimeter as the detector. The metals determined are Mg, Ca, Sr, Ba, Fe(II), Fe(III), Co, Ni, Cu, Zn, the lanthanides, Th, Al, Ga, In, Pb and Bi. The detection limits (three times the baseline noise) range between 2 and 100 μg l?1, depending on the analyte, for a 200-μl injection. To demonstrate the quantitative performance of the detector, the zinc and aluminium contents of a fresh water certified reference material was determined and gave good agreement with the certificate values. 相似文献
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Gusmão R Díaz-Cruz JM Ariño C Esteban M 《The journal of physical chemistry. A》2012,116(25):6526-6531
The behavior of selenocystine (SeCyst) alone or in the presence of various metal ions (Bi(3+), Cd(2+), Co(2+), Cu(2+), Cr(3+), Ni(2+), Pb(2+), and Zn(2+)) was studied using differential pulse voltammetry (DPV) over a wide pH range. Voltammetric data matrices were analyzed using chemometric tools recently developed for nonlinear data: pHfit and Gaussian Peak Adjustment (GPA). Under the experimental conditions tested, no evidence was found for the formation of metal complexes with Bi(3+), Cu(2+), Cr(3+), and Pb(2+). In contrast, SeCyst formed electroinactive complexes with Co(2+) and Ni(2+) and kinetically inert but electroactive complexes with Cd(2+) and Zn(2+). Titrations with Cd(2+), Co(2+), Ni(2+), and Zn(2+) produced data that were reasonably consistent with the formation of stable 1:1 M(SeCyst) complexes. 相似文献