胶束介质在速差动力学分析中的应用

本文主要报道溴化十六烷基三甲胺(CTMAB)表面活性剂在速差动力学分析中的应用,并用于高温合金试样中钼和钛的同时测定,在CTMAB存在下,3,5-二溴水杨基荧光酮(3,5-DBSF)与钼、钛形成三元配合物,其灵敏度比二元配合物分别提高了5.4和17.3倍,且由于胶束介质的存在,扩大了两组分形成配合物反应速率的差别,大大改善了方法的选择性。铝(III)、钙(II)、钴(II)、铬(III)、铜(II)、铁(II)、镁(II)、镍(II)等元素的允许量均在毫克级以上。钼的三元配合物形成速率较快,20秒内基本反应完全,钛的反应速率较慢,10分钟才达到平衡,基于两组分反应速率差别,采用对数外推法,经微机计算处理,进行了高温合金中钼、钛的同时测定,其相对偏差在5%以内。     

三次标准加入光度法同时测定铁钴镍的研究

利用在乙酸缓冲溶液中铁、钴、镍与１－亚硝基－２－蔡酚－３,６－二磺酸钠（ＮＲＳ）生成有色配合物的反应,结合在两次标准加入法原理的基础上,提出了三组分同时测定的三次标准加入法,并应用于铁、钴、镍的同时测定。为消除组分间协同效应所引起的吸光度加合性的偏离,定义了三组分协同效应系数,并将其引入三组分同时测定方法,补偿吸光度对线性的偏离;补偿后铁、钴、镍的测定线性范围分别为０．０３～３．５０,０．０５～３     

K系数分光光度法同时测定钴矿中铜、钴、镍

探讨了在pH 8.00时,溴化十六烷基三甲基铵在存下,铜(Ⅱ)、钴(Ⅱ)和镍(Ⅱ)与二甲酚橙显色的反应条件.建立了K系数分光光度法同时测定钴矿中铜、钴、镍的分析方法.铜、钴、镍含量分别在0～800 μg·L-1,0～1.60 mg·L-1,0～1.20 mg·L-1范围内符合比耳定律.方法用于钴矿试样的分析,测得铜、钴、镍的相对标准偏差分别为3.5%,4.9%,3.4%,回收率分别为103.3%,92.6%,99.0%.     

分光光度法同时测定微量铁和钴

在碱性介质中,铁(Ⅱ)和钴(Ⅱ)可与硫代巴比妥酸-NO2-体系反应分别形成一种稳定的兰色和黄色配合物,铁(Ⅱ)配合物在656nm和386nm具有吸收峰,钴(Ⅱ)配合物只有一个吸收峰位于423nm,体系的吸光度A6Fe56、A4F2e3、AC42o3与铁、钴含量在一定的范围内呈良好的线性关系,且铁(Ⅱ)、钴(Ⅱ)配合物在423nm波长处的吸光度具有良好的加和性,建立了一种同时测定微量铁和钴的新的分光光度法。方法的线性范围分别为铁0～50μg/(25mL)、钴0～25μg/(25mL)。将该法应用于水样中微量铁和钴的同时测定,其结果分别与原子吸收光谱法和紫尿酸光度法相吻合,加标回收率分别为98%～102%和94%～106%,相对标准偏差(RSD)分别为1.0%～1.8%和3.1%～4.7%(n=5)。     

2-乙基己基膦酸单(2-乙基己基)酯-H2SO4-钴(Ⅱ)、镍(Ⅱ)萃取体系中所形成的配合物研究

制备了一元酸性磷(膦)酸酯类萃取剂(HL)二(2-乙基已基)磷酸(P-204)和2-乙基已基膦酸单(2-乙基已基)酯(P-507)与钴(Ⅱ)、镍(Ⅱ)的配合物。通过元素分析、水含量测定、热重分析、红外和电子光谱及磁矩测定就二种萃取剂与钴、镍配合物的组成、性质和立体构型进行了比较研究。结果表明,二种配体所形成的配合物是相似的。深兰色的钴配合物CoL_2为四面体构型。棕色的镍的无水配合物NiL_2和绿色的含水配合物NiL_2·2H_2O对均为八面体构型。四面体钴配合物中键的共价性程度大于八面体的镍配合物。     

铁（Ⅲ）、钴（Ⅱ）和镍（Ⅱ）的三（2－苯并咪唑甲基）胺配合物催化环己烯的氧化反应

铁（Ⅲ）、钴（Ⅱ）和镍（Ⅱ）的三（２－苯并咪唑甲基）胺配合物催化环己烯的氧化反应吕正荣，殷元骐，金道森（中国科学院兰州化学物理研究所，兰州７３００００）关键词铁（Ⅲ）配合物，钴（Ⅱ）配合物，镍（Ⅱ）配合物，环己烯氧化反应．与含血红素的氧化酶相比，人们...     

借化学性质差异分光光度同时测定镍和钴

利用高氯酸对镍和钴的乙基黄原酸盐配合物的化学作用差异,不分离测定混合物中两组分,是同时光度测定的又一种类型。     

2-(2′-咪唑偶氮)苯酚-4-磺酸吸光光度法测定钴的研究

研究了咪唑偶氮苯酚-4-磺酸(IAP-4S)与Co(Ⅱ)显色反应的适宜条件,应用拟定方法测定了钴镍混合试样中两组分的含量和标准合金样品中的钴含量,结果令人满意。     

超临界二氧化碳中卟啉与钴(II)、镍(II)、锌(II)配合物反应动力学

用紫外-可见光谱研究了钴(II)、镍(II)、锌(II)的1,1,1,5,5,5-六氟-2,4-戊二酮-二水配合物[M(hfac)2(H2O)2,M=Co、Ni、Zn]与5,10,15,20-四(五氟苯基)卟啉[H2tpfpp]在超临界二氧化碳中反应生成金属卟啉[M(tpfpp)]的反应动力学.在金属配合物大大过量时,反应对卟啉为一级.其表观一级速率常数随钴(II)、镍(II)配合物的浓度增加先增加、而后趋于稳定,而表观一级速率常数随锌(II)配合物的浓度增加线形增加.根据实验事实,讨论了反应的机理,得到了相应的热力学和动力学参数.     

1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮与对氨基苯乙酮的缩合反应、量化计算和抑菌活性

利用1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(PMBP)和对氨基苯乙酮(PAAP)制备了PMBP缩对氨基苯乙酮(PMBP缩PAAP)及其铜(Ⅱ)、钴(Ⅱ)、镍(Ⅱ)和锌(Ⅱ)配合物,根据元素分析、红外、紫外、MS和1H NMR谱表征了结构.利用量子化学和分子力学计算方法对缩合反应的机理进行了探讨,较好地解释了PMBP-PAAP配体的烯胺酮式构型及其配合物的亚胺烯醇式构型.测定了化合物对大肠杆菌和金黄色葡萄球菌的抑制活性,其中以钴(Ⅱ)和铜配合物(Ⅱ)的抑菌活性最佳.     

镍-二甲酚橙-溴化十六烷基三甲铵动力学光度法测定镍

研究了Ni2+与二甲酚橙及溴化十六烷基三甲铵形成三元络合物的反应特性，测定了反应级数和表观活化能．基于该络合反应速率较小的特性，采用对数外推法计算机处理数据，建立了停流－动力学测定Ni2+的新方法．大多数元素的干扰均可用动力学方法消除，应用于镍矿等实样中镍的测定，结果满意，其相对标准偏差小于3％。     

Simultaneous differential kinetic determination of cobalt and nickel based on on-line complex formation and ligand substitution reaction using a stopped-flow FIA system

A differential kinetic method utilizing a stopped-flow FIA system is proposed for the simultaneous determination of cobalt and nickel at sub-ppm levels in mixtures. The method is based on the large difference in the rates of the ligand substitution reaction of the metal complexes of 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)aniline (PSAA) with nitrilotriacetic acid. The apparent reaction rate for the Ni-PSAA complex is more than 100 times larger than that for Co-PSAA complex. The relative standard deviations in the analysis of binary mixture of 0.50 g/ml cobalt and 0.30 g/ml nickel were 1.9% and 2.1%, respectively (n=7). The sample throughput is about 20 h^–1. The effect of various ions was also studied. The proposed method has satisfactorily been applied to synthetic samples containing different ratios of cobalt and nickel 1/12 to 10/1.     

Simultaneous spectrophotometric determination of cobalt and nickel by partial least square regression in micellar media

Diphenycarbazone has been used for the simultaneous determination of cobalt and nickel by partial least square regression method. DPC complexes of cobalt and nickel at pH 7-10 are of pink color, which are soluble in TX-100 micellar media. A partial least square multivariate calibration method for the analysis of binary mixtures of cobalt and nickel was developed. The total relative standard error for applying the PLS method was calculated. The accuracy and reproducibility of the determination method for various known amounts of Co(II) and Ni(II) in their binary mixtures were tested. The effects of diverse ions on the determination of cobalt and nickel to investigate the selectivity of the method were also studied. The proposed method was applied to the synthetic binary mixtures, alloys and pharmaceutical samples.     

钴(II)-联吡啶-α-氨基酸的热力学和动力学研究

关于联吡啶为第一配体的二元、三元配合物的热力学和动力学性质的研究,以铜（Ⅱ）作为中心离子最为多见,而以钴（Ⅱ）作为中心离子的报导较少．实验表明,过渡金属钻（Ⅱ）能与大多数的生物配体、大π共轭体系形成相当稳定的二元、三元配合物,是生物功能模拟的一个具有应用价值的中心离子·钴（Ⅱ）卟啉可以代替铁（Ⅱ）卟啉,模拟血红蛋白、肌红蛋白[1],在生物体内起到输送氧的作用．为了充分了解钴（Ⅱ）与生物配体的配伍能力、配位方式以及其配位过程的动态行为,为推动钴（Ⅱ）配合物及其生物功能的模拟研究,本文分别采用PH电位法…     

Spectrophotometric simultaneous determination of cobalt, copper and nickel using nitroso-R-salt in alloys by partial least squares

Partial least squares modeling as a powerful multivariate statistical tool applied to spectrophotometric simultaneous determination of cobalt, copper, and nickel in aqueous solutions. The concentration range for cobalt, copper and nickel were 0.4-2.6, 0.6-3.4, 0.5-5.5 ppm, respectively. The experimental calibration set was composed with 36 sample solutions using a mixture design for three component mixtures. The absorption spectra were recorded from 470 to 600 nm. The effect of pH on the sensitivity and selectivity was studied according to net analyte signal (NAS). The values of root mean square difference (RMSD) for cobalt, copper and nickel using partial least squares (PLS) were 0.0192, 0.0263 and 0.0446 ppm, respectively. The effects of various cations and anions were investigated. The method was used to determination of cobalt, copper and nickel in two sample alloys based on copper, nickel and cobalt (known as cunico) and based on cobalt, nickel and iron (known as conife).     

Simultaneous kinetic determination of copper, cobalt and nickel by means of -group interchange reactions

The kinetic determination of copper, cobalt and nickel in binary and ternary mixtures without prior separation is described. The methods are based on the difference in the reaction rate of interchange of - groups between thiosemicarbazide and 6-methylpicolinaldehyde azine in the presence of these ions at pH 4.5. Through these reactions the corresponding metal thiosemicarbazone complexes are formed. Various ratios of these ions at the 10(-5)M level can be determined photometrically by either the logarithmic extrapolation method or a combined initial-rate and fixed-time method proposed here for the first time.     

Chromotropic acid azo dyes of the pyridine series Spectrophotometric determination of nickel and cobalt in the presence of many ions and their simultaneous determination

Pyridyl-2-azo-chromotropic acid (disodium salt) is proposed as a new reagent for the determination of nickel and cobalt in the presence of many ions and for their simultaneous determination in the absence of cyanide and EDTA. The wavelengths of maximum absorption for the nickel and cobalt complexes are 570 and 640 mmu respectively. Beer's law is obeyed by the complex systems from 0.125-0.8 ppm of nickel and 0.16-1.2 ppm of cobalt. The optimum concentration ranges are 0.25-0.8 ppm for nickel and 0.16-1.2 ppm for cobalt and the relative error is 2.7 %. The molar absorptivities for the complexes of nickel and cobalt are 40,720 and 33,600, while the dissociation constants at pH 7.5 and 22 degrees are of the order of 10(-12) and 10(-13), respectively. The metal to reagent ratio is 1:3.     

High-performance liquid chromatographic determination of uranium using solvent extraction and bis(salicylaldehyde) tetramethylethylenediimine as complexing reagent

The reagent bis(salicylaldehyde)tetramethylethylenediimine has been used for the determination of dioxouranium(VI), based on complexation in aqueous solution at pH 6, followed by extraction in chloroform and HPLC determination on a Hypersil ODS (3 μm) column. The complex was eluted with the ternary mixture methanol-acetonitrile-water (40:30:30, v/v/v), with UV detection at 260 nm. Oxovanadium(IV), iron(III), copper(II), cobalt(II), nickel(II) and palladium(II) were completely separated and did not interfere in the determination of uranium. The linear calibration range and detection limits have been obtained. The method has been applied to the determination of uranium together with copper, iron and nickel in mineral ore samples.