Simultaneous direct determination of aluminum, calcium and iron in silicon carbide and silicon nitride powders by slurry-sampling graphite furnace AAS.

A fast and accurate analytical method was established for the simultaneous direct determination of aluminum, calcium and iron in silicon carbide and silicon nitride powders by graphite furnace atomic absorption spectrometry using a slurry sampling technique and a Hitachi Model Z-9000 atomic absorption spectrometer. The slurry samples were prepared by the ultrasonication of silicon carbide or silicon nitride powders with 0.1 M nitric acid. Calibration curves were prepared by using a mixed standard solution containing aluminum, calcium, iron and 0.1 M nitric acid. The analytical results of the proposed method for aluminum, calcium and iron in silicon carbide and silicon nitride reference materials were in good agreement with the reference values. The detection limits for aluminum, calcium and iron were 0.6 microg/g, 0.15 microg/g and 2.5 microg/g, respectively, in solid samples, when 200 mg of powdered samples were suspended in 20 ml of 0.1 M nitric acid and a 10 microl portion of the slurry sample was then measured. The relative standard deviation of the determination of aluminum, calcium and iron was 5 - 33%.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝

采用硝酸、盐酸、氢氟酸(氟化氢铵)、高氯酸分解样品,电感耦合等离子体原子发射光谱法测定了再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝的量。其测定范围:ω(Cu):0.01%～0.60%;ω(Pb):0.10%～5.00%;ω(Fe):0.10%～5.00%;ω(In):0.0100%～0.200%;ω(Cd):0.010%～3.00%;ω(As):0.10%～2.00%;ω(Ca):0.10%～10.00%;ω(Al):0.10%～4.00%。各元素的加标回收率为93%～113%。方法准确、快速、可靠,适用于再生锌原料中铜、铅、铁、铟、镉、砷、钙、铝量的同时测定。     

Ion exchange chromatography of aluminum using 3-carboxy-2-naphthylamine-N,N-diacetic acid as a fluorescent post-column chelating reagent

Ion exchange chromatography of aluminum ion using 3-carboxy-2-naphthylamine-N,N-diacetic acid (CNDA) as a fluorescent post-column chelating reagent was studied. The solution containing ammonium chloride and hydrochloric acid was used for the eluent, and acetate buffer solution containing CNDA was used for the post column chelating reagent. The peak of aluminum was separated from that of calcium, magnesium and zinc, and the chromatogram was not affected by copper(II) and iron(III). The calibration curve gave linear plots with a range of 0.0027-0.54 ppm aluminum, the regression coefficient of correlation (r2) was 1.000, and the detection limit (S/N = 3) was 0.3 ppb, indicating that the method could determine aluminum with high sensitivity. It was demonstrated that CNDA is a useful metallofluorescent reagent for aluminum. This method has been successfully applied to the determination of aluminum in some tea drinks.     

The role of the trivalent metal in an LDH: Synthesis, characterization and fire properties of thermally stable PMMA/LDH systems

Two layered double hydroxides (LDHs), calcium aluminum undecenoate (Ca₃Al) and calcium iron undecenoate (Ca₃Fe), have been prepared by the co-precipitation method. XRD analysis of these LDHs reveals that they are layered materials and FT-IR and TGA confirmed the presence of the undecenoate anions in the material produced. The PMMA composites were prepared by bulk polymerization and the samples were characterized by XRD, TEM, TGA and cone calorimetry. Both additives greatly enhance the thermal stability of PMMA, while the calcium aluminum LDH gives better results when the fire properties were examined using the cone calorimeter.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定铸造用硅砂中的Fe2O3、Al2O3、CaO、MgO、TiO2、K2O、Na2O

建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定铸造用硅砂中Fe_2O_3、Al_2O_3、CaO、MgO、TiO_2、K_2O、Na_2O的方法。研究了溶样方法的选择优化,采用硝酸、氢氟酸溶样,冒高氯酸处理,通过元素分析线的选择,基体和共存元素影响的消除,在最佳的仪器分析条件下得出了方法的线性范围、相关系数及检出限。用硅砂3个梯度含量的标准物质的分析结果评价方法的准确度和精密度。方法的检出限Fe为0.012μg/mL、Al为0.032μg/mL、Ca为0.27μg/mL、Mg为0.003 2μg/mL、Ti为0.002 1μg/mL、K为0.16μg/mL,Na为0.000 44μg/mL。5次数据的相对标准偏差说明方法稳定性较好。方法适用于铸造用硅砂中Fe_2O_3、Al_2O_3、CaO、MgO、TiO_2、K_2O、Na_2O含量的测定。     

Spectrophotometric determination of aluminum and iron in calcium

A simple, rapid, and accurate method is described whereby micro amounts of aluminum and iron can be determined in calcium metal. The iron is determined spectrophotometrically by measuring the absorbency of the reddish-orange color of the tris(1,10-phenanthroline)iron(II)ion, [(C₁₂H₈N₂)₃Fe]⁺⁺. This complex effectively removes the iron interference, and the aluminum is determined spectrophotometrically in the solution remaining from the iron determination by extracting it with a chloroform solution of 8-quinolinol and measuring the absorbency of the yellow color of the tris(8-quinolinolo)aluminum(III) in the chloroform solution.     

Separation of microgram quantities of aluminum and iron(III)

The separation of microgram quantities of ferric iron and aluminum can be effected by passage of an acidic thiocyanate solution through the anion exchange resin Amberlite IRA-400A. The anionic complex of iron and thiocyanate remains on the column whereas aluminum passes through with the eluate. This method has been utilized in the separation of up to 200 μg of iron from comparable amounts of aluminum thus permitting the spectrophotometric determination of the latter in caustic liquors and other alkali products.     

流动注射胶束增溶分光光度法同时测定镁砖中微量铁铝

本文研究了铁铝－ＣＡＳ－乳化剂ＯＰ胶束增溶体系的ＦＩＡ－光度法时测定镁砖中微量铁铝，该法操作简便，快速可靠，进样频率４５样次／ｈ，ＲＳＤ＜３．４％和５．８％。结果令人满意。     

分光光度法同时测定硅石中的铁和铝

在邻二氮菲(Phen)、铬天青S(CAS)和十四烷基二甲基苄基氯化铵(TDMBA)的共同存在下,于pH 5～6的酸性介质中,铁、铝分别生成Fe-Phen和Al-CAS-TDMBA络合物,用同一份试液,在波长510 nm测定铁,在625 nm测定铝,两种络合物互不干扰。用该法可同时测定硅石中的铁和铝。     

铁和钛的同时分光光度测定及其几种方法的比较

考查了用二安替比林甲烷(DAM)光度测Fe(Ⅲ)的条件,测定了Fe(Ⅲ)-DAM的组成及K_稳,提出用DAM在一份试液中不经分离或掩蔽而同时用分光光度法测定不同含量比的微量铁和钛的八种方法,在相应条件下效果均好。用于多种铝合金分析,精密度及回收率皆称满意,方法简便、快速。     

鼓风炉渣中氧化钙的测定方法改进

在参照DHF83-B多元素快速分析仪法测定炉渣中氧化钙的基础上,对鼓风炉渣中氧化钙的测定方法进行了改进。用盐酸（1+1）溶样,三乙醇胺掩蔽残留的铁、铝、锰等元素,以钙指示剂作指示剂,于pH值大于12时用EDTA标准溶液滴定氧化钙。EDTA滴定法分析结果的相对标准偏差RSD为2.82%,与DHF83-B多元素快速分析仪法比较,其结果基本一致。该方法具有准确度好、快速简便等优点,适合用于冶炼炉渣中氧化钙含量的测定。     

Salicylaldehyde guanylhydrazone as an analytical reagent for spectrophotometric estimation of iron

The properties and analytical possibilities of salicylaldehyde guanylhydrazone as spectrophotometric reagent have been examined. A new method for the determination of iron has been developed. Iron can be determined in the presence of the oxalate, tartrate, citrate, aluminum, and others.     

异丙醇铝合成中原料铝所含铁杂质与异丙醇反应活性研究

理论上金属铁与异丙醇是不发生化学反应的. 针对异丙醇铝合成反应中, 金属铝原料所含铁杂质与醇生成含铁低沸点有机物这一事实, 研究了体相铁对铝中铁杂质与异丙醇反应的影响, 同时研究了不同含铁量铝片/铁铝合金中铁杂质与异丙醇反应的规律. 反应产物经减压蒸馏后用电感耦合等离子体原子发射光谱方法(ICP-AES)进行铁含量分析. 基于实验结果和理论分析提出了小尺寸铁微粒高反应活性的反应机理. 并对产品采用元素分析, ¹H NMR, IR进行初步表征.     

The determination of aluminum,nickel, cobalt,copper, and iron in alnico

A method has been developed for the determination of the major constituents of Alnico based on an anion exchange separation of the chloride complexes and the subsequent determination of aluminum, nickel, copper, cobalt and iron with EDTA. The method is more convenient than conventional classical methods.     

Phosphate rock treatment with citric acid for the rapid potentiometric determination of fluoride with ion-selective electrode

A fast method for sample treatment of phosphate rock has been developed for the purpose of quantitative leaching (98-100%) of fluoride but less of the interfering cations such as iron and aluminum. Citric acid (0.5 M) was used to extract fluoride in 15-45 min. Leaching of iron and aluminum is minimal, and these ions are complexed with citric acid. The leaching method was optimized with respect to sample size, citric acid concentration, leaching time and temperature. The analysis was completed by the rapid determination of fluoride with ion-selective electrode. The proposed treatment method was applied to phosphate rock samples from Jordan and Morocco and yielded accurate results as compared to the standard steam distillation from strong acid solution followed by thorium nitrate titration.     

Determination of aluminum in highly concentrated iron samples: Study of interferences using high-resolution continuum source atomic absorption spectrometry

High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) has been used to investigate spectral and non-spectral interferences found with a conventional line source atomic absorption spectrometer in the determination of aluminum in pharmaceutical products containing elevated iron and sugar concentrations. A transversely heated graphite furnace was used as the atomizer in both spectrometers. The two most sensitive aluminum lines at 309.3 nm and 396.2 nm were investigated and it was found that an iron absorption line at 309.278 nm, in the vicinity of the aluminum line at 309.271 nm, could be responsible for some spectral interference. The simultaneous presence of iron and the organic components of the matrix were responsible for radiation scattering, causing high continuous and also structured background absorption at both wavelengths. The aluminum and iron absorption could not be separated in time, i.e., the iron interference could not be eliminated by optimizing the graphite furnace temperature program. However, an interference-free determination of aluminum was possible carrying out the measurements with HR-CS AAS at 396.152 nm after applying least squares background correction for the elimination of the structured background. Analytical working range and other figures of merit were determined and are presented for both wavelengths using peak volume registration (center pixel ± 1) and the center pixel only. Limits of detection and characteristic masses ranged from 1.1 to 2.5 pg and 13 to 43 pg, respectively. The method was used for the determination of the aluminum contamination in pharmaceutical formulations for iron deficiency treatment, which present iron concentrations from 10 to 50 g l^− 1. Spike recoveries from 89% to 105% show that the proposed method can be satisfactorily used for the quality control of these formulations.     

Sorption Recovery of Lanthanum,Iron, Aluminum,and Calcium Ions from Phosphoric Acid

Russian Journal of Applied Chemistry - Sorption recovery of lanthanum, iron(III), aluminum, and calcium ions from phosphoric acid solutions with MTC 1600 macroporous sulfonic cation exchanger under...     

Mono-substitution of iron pentacarbonyl metal hydride: facilitation

Controlling the degree of substitution of iron pentacarbonyl with neutral ligands has usually been difficult. Conditions are reported whereby considerable control may be exercised over the substitution of iron pentacarbonyl; with PPh₃ the ratio of mono-/disubstitution may be varied over a range of 50. The substituted iron carbonyl complexes were obtained by treating iron pentacarbonyl with lithium aluminum hydride or sodium borohydride in refluxing THF in the presence of a variety of neutral ligands. The method is particularly useful for a simple high yield synthesis for monosubstituted iron carbonyls.     

Potentials of Electron Probe Microanalysis in Studying Zircons

Potentials of electron probe microanalysis in determining hafnium, uranium, thorium, lead, niobium, titanium, manganese, iron, chromium, calcium, aluminum, tin, tungsten, yttrium, and lanthanide impurities in zircons have been studied. It was found that the background signal depends on the composition of the zircon crystal, including the concentration of hafnium. Methods have been proposed to improve the measurements of the background intensity and to optimize analytical conditions for attaining the lowest detection limits.     

流动注射光纤荧光探针动力学法测定铁的研究

研究了8-苯胺基-1-萘磺酸作为表面活性剂胶束荧光探针的性质,并将其用作动力学分析的荧光指示剂。建立了以铁(Ⅲ)催化过氧化氢氧化ANS-Brij35体系荧光猝灭反应为基础,用流动注射和光导纤维技术测定痕量铁的动力学分析新方法。该法线性范围为5～300ng/mL,检测下限为2ng/mL,绝对检出量为0.2ng,对20ng/mL铁(Ⅲ)进行11次测定相对标准偏差为0.27%,可直接用于人发、纯铝和铝合金中铁的测定。