火焰原子吸收光谱法测定芦荟中锰、铁、铜、锌、镍、钴

１　　引　　　　言芦荟作为药用和保健品越来越引起人们的重视。近年来人们将它作为良好的防癌、抗癌药品而食用。芦荟的主要成分为淡黄色结晶性甙,为芦荟大黄素甙,水解产生ｄ－阿拉伯胶糖、芦荟大黄素等。它有良好的抑菌作用,对表皮癣菌、星形奴卡氏菌等皮肤真菌均有不同的抑制作用。主治烧烫伤、肝经实热等症。还能治疗糖尿病、痔疾、中耳炎、减肥等多种疾病。是人们理想的保健品和药品。芦荟中的金属元素的分析,作者未见文献报道。本文用原子吸收光度法测定了３种芦荟中锰、锌、铜、铁、镍、钴的含量,得到了满意的结果。２　　实验…     

Electrothermal Atomic Absorption Spectrometric Determination of Cobalt,Copper and Nickel in Fresh Water After Their Preconcentration by Precipitate Flotation

Abstract

A method is developed for simultaneous separation and determination of μg/L levels of Co(II), Cu(II) and Ni(II) in fresh water by precipitate flotation. The optimal conditions of the experimental procedure with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors were investigated. The pH interval of the working medium, within which Co(II), Cu(II) and Ni(II) can be successfully separated, was determined from the aspect of collectors and surfactant stability. The amounts of the elements investigated were determined by electrothermal atomic absorption spectrometry. The detection limit of the method is 0.15 μg/L for cobalt, 0.03 μg/L for copper and 0.79 μg/L for nickel.     

方波伏安法同时测定食物中的铜、铅、锌、镉、铁、钴、镍、锰

经过预处理的食物样品:在马福炉中灰化24h,加HNO_3、HClO_4蒸干。残渣用HC1O_4-酒石酸底液提取。首先用方波阳极溶出伏安法测定其中Cu、Pb、Zn、Cd。然后加入氨水使pH约为9.5,用方波阴极伏安法测定Fe、Mn。最后加入丁二酮肟溶液,用方波吸附伏安法测定Ni、Co。     

Transferable Pair Potentials for Liquid Iron,Cobalt and Nickel

Effective inter-ionic pair potentials for liquid iron, cobalt and nickel are derived from second order pseudopotential perturbation theory with the transferable electron-ion potential of Fiolhais and co-workers which was originally developed for the solid state. The liquid structure is obtained by the thermodynamically self consistent liquid state theory, the variational modified hypernetted chain (VMHNC) approximation. It has been found that the calculated structural properties at the investigated thermodynamic states just above the melting point agree well with experiment. In this work we have determined the parameters of liquids Fe, Co and Ni for the universal choice of the evanescent core pseudopotentials of Fiolhais'. We have shown that this pseudopotential is transferable to the liquid state if used this parameterisation.     

Coordination Compounds of Cobalt, Nickel, and Copper with Isonitrosoacetone Benzoylhydrazone

Benzoylhydrazine, isonitrosoacetone react in ethanol with cobalt, nickel, copper halides andacetates to give the coordination compounds MX₂(HL) · nH₂O, MX₂(HL)₂ · nH₂O, and ML₂ · nH₂O [M = Co,Ni, Cu; X = Cl, Br; HL = C6H5C(O)NHNC(CH3)CHNOH; n = 1-4]. The same reactions performed in the presence of sodium acetate and pyridine (pH 7-8) yield the complexes MLCl · nH₂O and MPy₂LCl ·nH₂O (n = 1-4). All the complexes have a pseudooctahedral coordination geometry. The hydrazone HL behaves as a tridentate O,N,N-donor ligand. Thermolysis of the substances involves dehydration (70-90°C), deaquation (155-170°C) or deamination (175-195°C), and complete thermal decomposition (285-360°C).     

沉淀分离金-电感耦合等离子体原子发射光谱法测定镀金溶液中铁、钴、镍、铜、银、铅

提出了用电感耦合等离子体原子发射光谱法测定镀金槽液中铁、钴、镍、银、铜及铅6元素,镀液中的金预先用硫酸及过氧化氢沉淀法予以分离,对试样的处理,沉淀分离,AES测定及仪器工作参数等分析条件作了试验并予以优化,测得上述6元素的检出限(3S)在0.002 4～0.067 mg·L-1之间.按所提出方法分析了两种低氰镀金槽液样品,并在此基础上加入不同量的6元素标准溶液后进行回收试验,所得回收率在83.0%～120.0%之间,相应测定值的相对标准偏差(n=5)在2.36%～11.839,6之问.     

Polarographic Determination of Cobalt and Nickel in Iron Meteorites

Abstract

Cobalt and nickel were determined in five iron meteorites by a polarographic method. The analyses gave good precision and are believed to be reliable. The nickel content ranged from 6.49% to 8.07%, and cobalt ranged from 0.40% to 0.49%. Atomic absorption measurements were made on the sample solutions for comparison.     

Investigations of Cobalt, Nickel, and Copper Diethyldithiocarbamates Using Thermal Lens Spectrometry

Thermal lens spectrometry was used to study the dissociation kinetics of diethyldithiocarbamate complexes of copper(II), cobalt(III), and nickel(II) as a function of pH in the presence of chloride and sulfate ions. It is shown that, as distinct from conventional spectrophotometric and potentiometric measurements, the reversible dissociation of the test complexes and the irreversible oxidation of the ligand can be studied separately (at a level of n × 10^–8–n × 10^–6 M) using thermal lens spectrometry. Because of work in more dilute solutions and due account of the kinetic features of the systems in question, thermal lens spectrometry provides a higher accuracy of the determination of stability constants for diethyldithiocarbamate complexes of copper(II), cobalt(III), and nickel(II). The adsorption of the diethyldithiocarbamate complexes in question from water–ethanol solutions (1 : 3) on Silasorb C₁₈ silica is studied, and the adsorption constants are determined. The limits of detection of copper(II), cobalt(III), and nickel(II) diethyldithiocarbamates obtained in extraction–thermal-lens determination are n × 10^–8 M.     

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%.     

微柱高效液相色谱法测定环境样品中的铁、钴、镍、铜、锌、锰

研究了用 2-(2-喹啉偶氮 )-间苯二酚 (QAR)为柱前衍生试剂 ,以WatersXterraTM RP18(1 .0×5 0mm ,2. 5 μm)微柱为固定相 ,60 %的甲醇 (内含 0 . 5 %的醋酸 )为流动相 ,高效液相色谱分离、二极管矩阵检测器测定铁、钴、镍、铜、锌和锰的方法。根据信噪比 (S N =3 )得各金属离子的检测限分别为 :铁3 μg L、钴 4μg L、镍 2 μg L、铜 4μg L、锌 5 μg L、锰 8μg L ,方法用于环境样品中痕量铁、钴、镍、铜、锌、锰的测定 ,相对标准偏差在 1 . 6%～ 3 . 5 %之间 ,标准回收率为 93 %～ 1 0 7%。     

柱前衍生非水毛细管电泳分离钴、镍和铜

提出柱前衍生非水毛细管电泳分离金属离子的方法.应用新合成的2-(6-甲基-2-苯并噻唑偶氮)-5-二乙胺基酚作为柱前衍生试剂,乙醇和N,N-二甲基甲酰胺为非水溶剂,在6min内实现了钴、镍和铜的分离,灵敏度高,检测限分别为9.18×10^-8mol/L、2.79×10^-7mol/L和4.47×10^-7mol/L.考察了柱前衍生条件、非水溶剂配比以及分离参数对分离的影响.     

系数倍率法同时测定铁钴镍三组分的研究

本文运用了在乙酸缓冲液中铁，钴，镍与亚硝基红盐（ＮＲＳ）生成有色配合物光吸收的差异，分别采用系数倍率法消除相互之间的干扰取得了满意的结果。     

Cobalt,Nickel and Copper Complexes of Benzylamino-p-chlorophenylglyoxime. Thermal and thermodynamic data

Vic-dioxime ligandsand their metal complexes are used in analytical, bio, pigment and medicinal chemistry. Complexes of nickel(II), copper(II), and cobalt(II) with benzylamino-p-chlorophenylglyoxime (BpCPG) are synthesised. Thermal behaviour of these complexes was studied in dynamic nitrogen atmosphere by DTA, DTG and TG techniques. GC-MS combined system was used to identify the products during pyrolytic decomposition. The pyrolytic end products were identified by X-ray powder diffraction. Thermoanalytical data of these complexes are presented in this communication. Interpretation and mathematical analysis of these data and evaluation of order of reaction, the energy and entropy of activation based on the integral method using the Coats-Redfern equation and the approximation method using the Horowitz-Metzger equation are also given. The metal complexes undergo decomposition in three stages and metal oxides remained as end products of the complexes. This revised version was published online in August 2006 with corrections to the Cover Date.     

同时测定合成样中铜钴镍钒含量的分光光度法--主成分回归法和偏最小二乘法比较

研究了主成分回归和偏最小二乘方法在多组分分光光度法分析中的应用,以５－Ｂｒ－ＰＡＤＡＰ（２〔５－溴－２－吡啶）－偶氮〕５－二乙氨基苯酚）为显色剂,ＯＰ（聚乙二醇辛基苯基醚）作为增溶增稳剂,在ｐＨ＝３．６的条件下,用主成分回归及偏最小二乘分光光度法同时测定了合成样中的铜、钴、镍、钒４组分含量,测定相对误差在－６．００％～４．００％之间。实验证明,对于加和性不好的体系偏最小二乘分光光度法要优于主成分回     

分光光度法同时测定石油制品中铁镍钒及钴的含量——小波变换-LSSVM算法的应用

石油产品样品经燃烧和灼烧除去碳氢化合物后,用稀盐酸溶解残渣,分取部分样品溶液用5-Br-PADAP作显色剂,对其中铁、镍、钒、钴的含量进行分光光度法同时测定.用试剂空白作参比溶液,在540～620 nm波长范围内每隔2 nm测定一次吸光度.所得数据用小波变换法处理以滤去分析信号中的噪声,然后用最小二乘支持向量机(LSSVM)算法解析所得分析数据.结果表明:LSSVM算法具有计算速度快,结果准确及泛化性能好等特点.用模拟样品对LSSVM算法进行预测,测得上述4元素的回收率在96.0%～103.5%之间.应用于分析实样时,所测得4元素结果与原子吸收光谱法的测得结果一致,所得结果的相对标准偏差(n=8)均小于4%.     

卡尔曼滤波极谱法同时测定镉,镍,锌,钴,铁,锰的研究（Ⅰ）

本文将ＪＰ－１Ａ极谱仪与计算机联机，进行Ｊ卡尔曼滤波极谱法同时测定镉（Ⅱ），镍（Ⅱ），锌（Ⅱ），钴（Ⅱ），铁（Ⅲ），锰（Ⅱ）的可行性研究。实验表明，在０．１０ｍｏｌ／Ｌ氯化钾，０．３０％亚硫酸钠，０．５０％水扬酸钠及在ｐＨ－８．０的氨性缓冲溶液中。上述离子的重叠峰解析良好，且不存在干扰问题。