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。     

Determination of P/Al ratio in phosphorus-doped aluminium oxide thin films by XRF,RBS and FTIR

Phosphorus-doped aluminium oxide thin films were deposited in a flow-type ALE reactor from AlCl₃, H₂O and from either P₂O₅ or trimethyl-phosphate. Structural information of the films was obtained from Fourier transform infrared (FTIR) spectra. Rutherford backscattering spectroscopy (RBS) was used to quantitatively determine the composition of the films. The P/Al intensity ratios calculated from X-ray fluorescence (XRF) results were in a linear relation with the P/Al concentration ratios calculated from RBS results. For comparison, the intensity ratios of the phosphorus peak (P=O) at about 1250 cm^–1 and the aluminium peak (Al-O) at about 950 cm^–1 were determined from the IR absorption spectra. The calibration of FTIR peak intensities was done by plotting the intensity ratios of phosphorus and aluminium peaks against the P/Al concentration ratios measured by RBS. FTIR gave also a linear calibration curve with RBS but the method is less suitable for routine analysis of P/Al ratio than XRF.     

Determination of sodium sulphate, calcium chloride and sodium chloride in gypsum plaster

Summary It has been shown that chloranilic acid and its salts can be used to determine sodium sulphate in the presence of calcium sulphate, calcium chloride in the presence of calcium sulphate, and sodium chloride in the presence of calcium chloride. The analysis is direct, the separation from non-desired components being carried out at the same time as the determination itself.One aspect of the use of chloranilic acid should be stressed, namely, that it sometimes is possible to differentiate between two salts that have the same anion but different cations, and examples have been given in this paper.     

SEM and AES depth profile studies of thin titanium and titanium oxide films covered by nanoscale evaporated Au layers

Thin titanium and titanium oxide films, both covered by ultra-thin gold layers, have been compared with titanium films after analysis, using a combination of SEM and AES. The Ti films were prepared under UHV conditions by evaporation on a glass substrate. The Ti oxide layers were prepared in situ by precisely controlled oxygen sorption at 298 K on Ti film. Both Ti and Ti oxide films were then covered in situ by a very thin Au layer. Analysis was performed in a separate system after long-term exposure of the films to air. SEM analysis revealed a much smaller size grain on the Au coated Ti films than on Ti films not coated with a Au layer. The thin gold layers covering the Ti surface prevent an extensive air interaction with Ti film. The analysis of the features of the Ti Auger spectra during the sputter profile measurements allow to characterise the chemical nature of Ti-oxide formed in Ti/Au interface region. Received: 7 September 1998 / Revised: 14 January 1999 / Accepted: 2 February 1999     

Calibration of sputtering yields for AES depth profiling of oxide layers on aluminium by means of carrier-gas heat extraction analysis

Summary For the purpose of obtaining suitable reference materials for technical coatings on aluminium, the feasibility of calibration of oxide layers by means of heat extraction was studied. Oxide layers were prepared on aluminium sheets by immersion in water of 50 or 80 ° C and annealing at 500 or 600 °C in argon atmosphere. The layer thickness was calculated from the oxygen content of the sample as measured by carrier-gas heat extraction analysis.The total sputtering yield of aluminium oxide layers was obtained via the correlation of AES depth profiling with heat extraction analysis results. This was demonstrated for high purity (99.9%) and technical purity (98.5%) aluminium with its original roughness from the rolling process, on which 20 to 1,000 nm thick oxide layers had been grown.The sputtering yields for the oxide layers prepared were found to be 3.9±0.8 atoms/ion, i.e., about four times higher than that for -Al₂O₃. Calibration of depth profiling on such technical quality oxide layers on aluminium was found to be feasible with a relative precision of 10 to 20%.

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Kalibrierung der Ionenzerstäubung zur AES-Tiefenprofilanalyse von Oxidschichten auf Aluminium durch Trägergas-Heißextraktion

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On leave from the Institute of Photographic Chemistry, Academia Sinica, Beijing, People's Republic of China     

Determination of carbon in solidified sodium coolant using new ICP-OES methods

New methods for the determination of carbon in sodium using laser ablation inductively coupled plasma optical emission spectrometry (LA-ICP-OES) and ICP-OES with pneumatic nebulisation (PN-ICP-OES) were developed. The determination was required for the study of the carbon dioxide reaction with molten sodium at high temperatures (300–600°C). After exposition to CO₂, the solidified sodium sample was subjected to direct solid analysis by LA-ICP-OES and to solution analysis. For the determination of carbon in the sodium sample surface layer by LA-ICP-OES, three different matrices containing sodium were tested (NaCl, NaF, and Na₂B₄O₇ · 10H₂O) as calibration pellets. The calibration dependences were improved using sodium as the internal standard. Average carbon content in the sodium bulk sample was determined by PN-ICP-OES after the sample dissolution by water vapour.     

Determination of aluminium and sodium in tungsten by non-destructive activation analysis

The sodium and aluminium content of tungsten has been measured by thermal neutron activation analysis. The concentration of aluminium was evaluated from the 1.78 MeV, and that of sodium from the 2.76 MeV full energy peaks. The minimum detectable concentrations of impurities were 0.04 microg of aluminium and 0.07 microg of sodium per 100 mg of tungsten.     

Determination of zirconium, barium, lanthanum, aluminium, sodium, hafnium and fluorine in fluorozirconate glasses

Summary A procedure is described for the determination of the cationic and anionic components in fluorozirconate glasses. Zirconium, barium, aluminium, lanthanum, sodium and hafnium were determined by inductively coupled plasma atomic emission spectrometry (ICP/AES) after dissolution of the sample with an acid mixture in a microwave oven. The fluorine content was evaluated with two different techniques, namely potentiometry with a fluoride ion-selective electrode (FISE) and ion chromatography (IC). In this case the sample was solubilized by fusion with sodium carbonate.     

Estimation of sodium in aluminium using the flame photometer

A flame photometric method of estmating sodium in aluminium has been developed. It was found that the concentration of aluminium altered the intensity of the sodium flame. This necessitated using standerd conditions.     

高压消解-ICP-AES法测定燃料油中钒铁镍硅铝钙钠硫

利用超声波处理制备样品,采用方差分析法进行均匀性检验。以HNO3和H2O2为溶剂,使用钢衬聚四氟乙烯罐高压消解样品,建立了以无机标准溶液制作校准曲线测定燃料油中元素的ICP-AES方法,实现了燃料油中V、Fe、Ni、Si、Al、Ca、Na、S等元素的同时测定。相应各元素的检出限为0.4、0.3、1.4、0.9、1.0、0.7、0.8、150 mg/kg;线性范围为1.3~500、0.9~500、4.1~500、2.8~500、3.0~500、2.1~500、2.4~500、450~45000 mg/kg。方法的相对标准偏差为0.1%~7.5%,回收率为96%~107%。本方法可以推广到其它相关石油产品中的元素分析。     

Nitrogen depth distribution, interface and structure analysis of SiNx layers produced by low-energy ion implantation

Thin silicon nitride (SiN _x ) layers with the stoichiometric N/Si ratio of 1.33 in the maximum of the concentration depth distributions of nitrogen were produced by implanting 10 keV¹⁵N ₂ ⁺ in 100 silicon at room temperature under high vacuum conditions. The depth distribution of the implanted isotope was measured by resonance nuclear reaction analysis (NRA), whereas the layer structure of the implanted region and the geometrical thickness of the layers were characterised by high resolution transmission electron microscopy (TEM). SiN _x layers with a thickness of about 30 nm were determined by NRA. Channeling Rutherford backscattering spectrometry was used to determine the disorder in the silicon substrate. Sharp interfaces of a few nanometers between the highly disordered implanted region and the crystalline structure of the substrate thickness were observed by TEM. The high thermal stability of SiN _x layers with N/Si ratios from under to over stoichiometric could be shown by electron beam rapid thermal annealing (1100 °C for 15 s, ramping up and down 5 °C/s) and NRA.     

Determination of calcium oxide in calcined phosphate ores

It has been shown that an existing procedure to differentiate calcium oxide from the carbonate and silicate of calcium can be used in the presence of the phosphate, fluoride and sulphate of calcium, and of the carbonate and oxide of magnesium. It is based on the reaction in aqueous solution of calcium oxide with sucrose to form calcium saccharate, and subsequent titration with oxalic acid solution. The method has application for a direct chemical determination of calcium oxide in phosphate rock where calcination of accompanying carbonate is necessary in beneficiation processes.     

ICP-AES法测定铸造铝合金中的痕量钙

采用ICP AES法研究铝轮毂用铸造铝合金中痕量钙的测定。以补偿法消除共存元素钛对钙的测定干扰。并运用铝基体工作曲线来消除铝基的影响,以提高分析的准确度。无需分离主体铝,方法的回收率在95.3%～105.5%之间,RSD≤5.5%。可满足铸造铝合金中钙质量分数大于0.001%的测定。     

电感耦合等离子体发射光谱法测定高效复合孕育剂中铝、钙、钡

通过硝酸、氢氟酸和盐酸分解试料,高氯酸冒烟驱走硅和氟,最后用盐酸溶解盐类,应用电感耦合等离子体发射光谱(ICP-AES)法对高效复合孕育剂中铝、钙、钡进行测定,此方法能准确、快速地测定其含量,回收率在98%～103%之间,精密度、标准样品分析对照均取得了满意的结果。     

Determination of sodium,potassium, calcium and magnesium cations in biodiesel by ion chromatography

This work reports an ion chromatographic (IC) method for the quantitative determination of inorganic cations (Na⁺, K⁺, Mg²⁺ and Ca²⁺) in biodiesel samples that were synthesized from different vegetable oils and fat. The proposed method uses water extraction, heating and ultrasound. The limits of detection (LOD) for each ion, in milligrams of the analyte per kilogram of biodiesel (mg kg⁻¹), were respectively: 0.11 (Na⁺); 0.42 (K⁺); 0.23 (Ca²⁺); and 0.36 (Mg²⁺). The accuracy of the method was studied through recovery tests. For comparison, two samples were also analyzed using an Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) procedure. The paired Student t test and the Snedecor F test showed that both methods offer equivalent results in terms of accuracy and precision. The operational simplicity, accuracy and precision of the proposed method suggest that it can be a good alternative for the determination of inorganic cations in biodiesel samples.     

Determination of radiostrontium in environmental samples using sodium hydroxide for separation of strontium from calcium

Summary Elérhetoség     

Trapping of transient processes in aluminium oxide thin films in a voltage pulse experiment

An experimental setup is presented that allows the trapping of transient states in potentiostatic and potentiodynamic experiments. The setup is suitable for electrochemical experiments as well as for dielectric investigations. The system stops an experiment by triggering at a predefined current level after a minimum time of the voltage pulse. The advantage of this device is demonstrated by means of a voltage pulse annealing procedure for a metal–insulator–metal (MIM) contact with an anodically prepared aluminium oxide film as insulator. The setup significantly increases the stability against a breakdown of the anodic oxide film.