壳聚糖富集FAAS法测定水中痕量Cu（Ⅱ）

了以壳聚糖作富集柱，稀H2SO4为洗脱剂，稀NaOH为再生剂，火焰原子吸收光谱法简便，快速分离集测定水中痕量Cu(Ⅱ）的方法，于波长325nm处测定，检出限为为20ng.ml^0-1，线性范围为10－20μg.ml^-1。     

在线微柱预富集流动注射火焰原子吸收测定水体中的Cu2+

流动注射;火焰原子吸收;在线微柱富集;Cu2+     

流动注射在线螯合树脂预富集火焰原子吸收光谱法测定痕量铜

研究了以国产D412螫合树脂作柱材料的流动注射在线微柱预富集火焰原子吸收光谱法测定铜的方法。选择了最佳的富集条件,在富集时间60s时,富集46倍,检出限为0.4ng·ml-1,(3σ),RSD为1.6％(20ng·ml-1Cu,n=11),分析速度为30次·h-1。井用此法进行水中痕量铜的测定。     

泡沫塑料富集–石墨炉原子吸收光谱法测定贝类水产品中痕量铊

采取微波消解的前处理手段消解样品,经泡沫塑料分离富集后,用石墨炉原子吸收光谱法测定贝类水产品中痕量铊。以1.5 mL Fe3+,2 mL H2O2和5%王水介质作为吸附体系将样品中铊分离富集,再以硝酸钯、抗坏血酸作为基体改进剂进行测定。铊的质量浓度在0～50μg/L范围内线性良好,相关系数为0.999 7,方法的检出限可达0.07μg/g。测定结果的相对别准偏差为1.53%～4.01%(n=7),加标回收率为87.1%～98.3%。泡沫塑料富集–石墨炉子吸收光谱法测定贝类水产品中痕量铊是一种准确、安全、便捷的检测方法。     

萃取富集-火焰原子吸收光谱法测定水中镍

探讨了有机溶剂萃取和有机相经加热蒸发相结合在富集分离水中镍的应用,结合火焰原子吸收光谱法,提高了灵敏度,设备简单,操作简便,方法检出限为4.10μg·L-1。     

PP(聚丙烯)-二苯氨基脲树脂分离富集原子吸收法测定地质样品中的银

研究了PP(聚丙烯)-二苯氨基脲树脂的合成及其分离富集样品中银的条件。于1mol／L的HCl介质中,银定量吸附在PP(聚丙烯)-二笨氨基脲树脂上,用0．5mol／L硫脲溶液洗脱,火焰原子吸收光谱法测定。回收率在96.4％～103．2％之间。可用于实际地质样品中贵金属的分离富集与测定。     

聚乙烯-双硫腙复膜树脂分离富集/原子吸收法测定地质样品中的痕量金

研究了聚乙烯双硫腙复膜树脂的合成及其分离富集痕量金的条件。于pH为2.0的HCl介质中,金离子被定量吸附在聚乙烯双硫腙复膜树脂上,并可用5%硫脲-0.1 mol/LHCl溶液洗脱,洗脱液用火焰原子吸收光谱法测定,金的回收率在91.5%~99.7%之间。本法可用于地质样品中痕量金的分离富集与测定。     

稀土元素分析

本文对 1998～ 2 0 0 0年间稀土元素分析化学方面的进展进行了综述 ,内容包括分离和富集方法、重量法和滴定法、分光光度法、分子荧光和发光法、原子吸收光谱法、原子发射光谱法、X射线荧光光谱法、质谱法、放射和电化学法及其它方法等。引用文献 6 6 0篇。     

PE(聚乙烯)-双硫腙复膜树脂分离富集原子吸收法测定地质样品中的钯

研究了PE(聚乙烯) 双硫腙复膜树脂的合成及其分离富集样品中钯的条件。于pH2.0的HCl介质中,钯定量吸附在PE(聚乙烯)-双硫腙复膜树脂上,用100g L乙二胺-20g LNaOH溶液洗脱,火焰原子吸收光谱法测定。回收率在94.5%～101%之间。可用于实际地质样品中贵金属的分离富集与测定。     

印迹壳聚糖/凹土分离富集-FAAS测定水中痕量镉

建立了用离子印迹壳聚糖/凹土(ⅡGA)分离富集-火焰原子吸收光谱(FAAS)测定痕量镉的新方法.在动态吸附条件下,系统地研究了溶液pH值、流速、洗脱条件和干扰离子对痕量镉分离富集的影响;在pH4.5、上样流速为0.60 mL/min的条件下,镉能被ⅡCA定量富集;吸附的镉可用1.0 mol/L HCl-0.1 mol/...     

火焰原子吸收光谱法测定粗铜中痕量铋、锑

粗铜样品经硝酸溶解,所得样品溶液中的铜离子在过量氨水中生成可溶性铜氨络离子,而铋、锑则以氢氧化铁和氢氧化镧作载体共沉淀,实现了富集铋、锑并与铜分离。基于此提出了原子吸收光谱法同时测定粗铜中的微量铋、锑。对浓盐酸的用量,硝酸铁和硝酸镧的加入量等试验条件进行了优化。铋的质量浓度在10 mg.L-1以内、锑的质量浓度在5 mg.L-1以内分别与其吸光度呈线性关系,检出限(3s)分别为0.06,0.04 mg.L-1,相对标准偏差(n=10)均小于2.0%。     

Preparation of Y2O3 nanoparticulate thin films using an emulsion liquid membrane system

Y2O3 nanoparticulate thin films have been prepared using an emulsion liquid membrane (water-in-oil-in-water (W/O/W) emulsion) system, consisting of Span 83 (sorbitan sesquioleate) as a surfactant and VA-10 (2-methyl-2-ethylheptanoic acid) as an extractant (cation carrier). Yttrium ions were extracted from the external water phase and stripped into the internal water phase to make precursor oxalate nanoparticles. Y2O3 nanoparticulate thin film was prepared by casting the W/O emulsion, separated from the external phase and containing the Y oxalate nanoparticles, on a Si substrate, followed by calcination in air. Well-arranged thin-layer nanoparticulate film, consisting of Y2O3 nanoparticles smaller than 20 nm, was obtained via spin coating of the W/O emulsion. A multilayer nanoparticulate thin film was also fabricated via a simple procedure of repeated coating and subsequent calcination.     

Study on the Determination of Cobalt,Nickel, Copper,Zinc and Vanadium in Environmental Samples by a Rapid High‐Performance Liquid Chromatography

A new method for the simultaneous determination of five transition metal ions in water and food by rapid high‐performance liquid chromatography was developed. The cobalt, nickel, copper, zinc and vanadium ions were pre‐column derivatized with 2‐(2‐quinolinylazo)‐4‐methyl‐1,3‐dihydroxidebenzene (QAMDHB) to form colored chelates, then the Co‐QAMDHB, Ni‐QAMDHB, Cu‐QAMDHB, Zn‐QAMDHB and V‐QAMDHB chelates were enriched by solid phase extraction with a C18 cartridge. The enrichment factor of 50 was achieved by eluting the retained chelates from the cartridge with tetrahydrofuran (THF). These chelates were separated on a ZORBAX Stable Bound rapid analysis column (4.6 × 50 mm, 1.8 um) with 68% methanol (containing 0.1% of acetic acid and 0.1% of CTMAB) as mobile phase at a flow rate of 2.0 mL/min and detected with a photodiode array detector from 450?600 nm. The Co‐QAMDHB, Ni‐QAMDHB, Cu‐QAMDHB, Zn‐QAMDHB and V‐QAMDHB chelates were separated completely within 2.0 min. The detection limits of cobalt, nickel, copper, zinc and vanadium are 2 ng/L, 1.5 ng/L, 2 ng/L, 3 ng/L, and 3 ng/L, respectively, in the original samples. This method was applied to the determination of the five transition metal ions in water and food samples with good results.     

Separation of copper (II) ions from humic complexes with oxine-impregnated emulsion globules

A water-in-oil type emulsion containing oxine has been used for the discrimination of copper(II) ions and copper-humic complexes in aqueous solutions. A toluene solution containing oxine and nonionic surfactant (Span-80) was vigorously mixed with 1 mol/L HCl by ultrasonic irradiation. The resulting emulsion was added to water and dispersed by stirring as numerous small globules. Copper(II) ions were quantitatively permeated across the oil layer and incorporated in the tiny droplets of HCl, whereas copper-humic complexes remained in the sample solution. After collecting the dispersed emulsion globules, they were destroyed by heating to segregate the aqueous (HCl) and organic (toluene) phases. The copper in the aqueous phase was determined by graphite-furnace atomic absorption spectrometry (GFAAS). The analytical results agreed with those obtained by the adsorption method, where negatively charged humic complexes were selectively collected on a macroreticular anion exchanger Sephadex A-25 column. The conventional liquid-liquid extraction did not offer a chemical speciation because copper(II) ions and humic complexes were simultaneously extracted into the organic phase. The proposed emulsion method was successfully applied to the analysis of river water samples.     

以铜离子为模板的褐藻酸凝胶对铜离子的选择性富集研究

以铜离子为模板，制备了褐藻酸凝胶（Cu-alginate)，通过吸附实验及过柱渗滤实验，试验了该吸附剂对铜离子的选择性吸附性能，并且采用该吸附剂富集了自来水中微量的Cu^2 ，结合原子吸收法测定了水样中Cu^2 的含量。结果表明：该吸附剂对Cu^2 有较高的选择性吸附性能，显著优于一些化学合成铜离子模板缩聚物及非铜模板褐藻酸凝胶（如Ca-alginate),非重金属离子（如K^ 、Na^ 、Ca^2 ）及某些重金属离子（如Ni^2 、Cd^2 ）等对Cu^2 的吸附均不产生明显干扰。用该吸附剂富集水中的微量铜离子，回收率可达97.7%。     

Separation of copper (II) ions from humic complexes with oxine-impregnated emulsion globules

A water-in-oil type emulsion containing oxine has been used for the discrimination of copper(II) ions and copper-humic complexes in aqueous solutions. A toluene solution containing oxine and nonionic surfactant (Span-80) was vigorously mixed with 1 mol/L HCl by ultrasonic irradiation. The resulting emulsion was added to water and dispersed by stirring as numerous small globules. Copper(II) ions were quantitatively permeated across the oil layer and incorporated in the tiny droplets of HCl, whereas copper-humic complexes remained in the sample solution. After collecting the dispersed emulsion globules, they were destroyed by heating to segregate the aqueous (HCl) and organic (toluene) phases. The copper in the aqueous phase was determined by graphite-furnace atomic absorption spectrometry (GFAAS). The analytical results agreed with those obtained by the adsorption method, where negatively charged humic complexes were selectively collected on a macroreticular anion exchanger Sephadex A-25 column. The conventional liquid-liquid extraction did not offer a chemical speciation because copper(II) ions and humic complexes were simultaneously extracted into the organic phase. The proposed emulsion method was successfully applied to the analysis of river water samples. Received: 14 April 1998 / Revised: 22 July 1998 / Accepted: 27 July 1998     

Separation of chitosan oligomers by immobilized metal affinity chromatography

A novel approach for chitosan oligosaccharide (COS) separation by immobilized metal affinity chromatography (IMAC) based on the differences in the interactions of chelated copper (II) ions with various COS (dimers, trimers, tetramers) is described. Polyhydroxylic chromatographic supports (agarose CL-6B and silica) were functionalized with various chelating functions such as iminodiacetate (IDA), carboxymethyl-aspartate (CM-Asp) and tris(carboxymethyl)ethylenediamine (TED). The COS retention capacities of the columns were between 2 and 6 mg/cm(3), depending on the chelating group. The COS were separated and/or enriched up to 95% for dimer and trimer and 90% for the tetramer, with yields of 60-95%.     

Weak exchange interaction supported by a biologically relevant long chemical bridge in a Cu-peptide model compound

The copper complex of the dipeptide L-alanyl-L-phenylalanine, catena-(L-alaninate-L-phenylalaninate-copper(II) monohydrate), identified as Cu(II)Ala-Phe, provides a convenient system to study a weak exchange interaction between unpaired spins transmitted through a biologically relevant long chemical bridge (18.34 A). In this complex, the copper ions are arranged in two symmetry-related anisotropic layers parallel to the ab plane at 13.17 A, separated by a double layer of water molecules. The equatorial-equatorial bridge considered as the most relevant path for exchange interactions between copper ions in neighbor layers contains 11 diamagnetic atoms (including three hydrogens), with two covalent amidate bridges plus three weak and moderate H bonds that go across the water layer. This interaction was studied using electron paramagnetic resonance in single-crystal samples, at 9.5 and 34.5 GHz. The measured magnitude of the interlayer interaction, |J3|/kB = 1.7(2) x 10(-3) K, is discussed in terms of values obtained for similar paths in other model compounds and in proteins. These results in model systems provide information that may be important in understanding biological functions at the molecular level.     

Ultratrace determination of lead,cadmium and copper in environmental and biological samples by atomic absorption spectrometry after their separation and preconcentration using octadecyl silica membrane disks modified with a new n–s schiff base

Pb(II), Cd(II) and Cu(II) ions were separated and preconcentrated by solid-phase extraction on octadecyl-bonded silica membrane disks modified with a new S–N-containing Schiff base (bis-2-thiophenal propandiamine) (BTPD) followed by elution and atomic absorption spectrometric detection. The method was applied as a separation and detection method for lead(II), cadmium(II) and copper(II) in environmental and biological samples. Extraction efficiency and the influence of sample matrix, flow rate, pH, and type and minimum amount of stripping acid were investigated. The maximum capacity of the membrane disks modified by 4?mg of BTPD was found to be 668 ± 10, 480 ± 8 and 454 ± 7?µg of lead, cadmium and copper, respectively. The limit of detection of the proposed method is 0.25, 0.01 and 0.02?ng/mL for lead, cadmium and copper, respectively.     

Water-in-oil emulsion containing oxine for the collection of traces of copper(II) in water

An oil type emulsion containing tiny encapsulated droplets of hydrochloric acid has been used for the concentration of traces of copper(II) ions in water. Milligram quantities of oxine and a non-ionic surfactant (Span-80) were dissolved in 5-10 ml of chloroform and mixed vigorously with 3 ml of 1 mol/l hydrochloric acid by ultrasonic irradiation. The resulting water-in-oil type emulsion was gradually added to 50-500 ml of water sample and dispersed by stirring as numerous small globules (0.1 to 0.5 mm in diameter). The copper diffused through the chloroform layer into the small droplets of hydrochloric acid, which occurred quantitatively in the sample of pH 3-10. After separating the emulsion by sedimentation, it was demulsified by heating to segregate the aqueous and organic phases. The copper in the aqueous phase was successfully determined by GFAAS. The emulsion method allows to perform both extraction and back-extraction more easily and rapidly than the conventional liquid-liquid extraction method.