Quantitative Untersuchungen von Bauxiten Zentralgriechenlands mittels Atomabsorptionsspektroskopie und Flammenatomemission

Summary A rapid two-part procedure was described for the determination of the elements Al, Fe, Ti, Cr, Ni, V, Mn, Cu, Ag, Au, Ga, Si, Ca, Mg and K in bauxite samples from central Greece. After an NaOH decomposition and an HCl pressure decomposition as well as an aqua regia decomposition carried out in addition, an optimization of the measuring program in time was achieved by constant alternation of atomic absorption spectrometry and atomic flame emission. The elements Ga and Au were measured directly in their extracts using AAS.     

Application of experimental design for investigating the determination of titanium in glass ceramics by flame atomic absorption spectrometry

Interferences of the matrix elements of glass ceramics (Al, Mg, Na and Si) on the titanium signal obtained by atomic absorption spectrometry with a nitrous oxide/acetylene flame were studied by means of experimental design. Quadratic polynomials were chosen as the model; full factorial designs with two, three and four variables at three levels were applied. As expected, aluminium increased the titanium signal, while magnesium reduced it. All the investigated elements interfered nonadditively with the titanium signal; the standard addition method therefore does not provide accurate results. Graphic evaluation of the empirical response surfaces was used to establish optimum conditions for titanium; these surfaces were compared with the polynomial surfaces to check the models. The results obtained on interactions in the system are used with some thermodynamic data to estimate the nature of the compounds formed in the flame. The strong interferences on the titanium signal requires fairly close matrix matching between the standard and sample solutions. The proposed method allows the determination of 3–6% Ti in glass ceramics with a relative standard deviation of 1%.     

Inter-laboratory comparison of the chemical analysis of silicon nitride

Summary The results of a round robin for the determination of nitrogen, oxygen and carbon and the common metallic impurities like Al, Ca, Fe, Mg and Na in silicon nitride are reported. The following analytical methods have been tested: nitrogen by acid decomposition under pressure followed by Kjeldahl distillation; oxygen by carrier-gas hot extraction; carbon by combustion in oxygen and infrared detection; metallic impurities after acid decomposition under pressure and evaporation of silicon fluoride by AAS or ICP-OES.     

糙米、胚芽米、精白米中多种矿质元素和B族维生素含量的比较研究

对产自黑龙江省绥化市的同一批粳稻分别进行加工制得糙米、胚芽米和精白米,经过干灰化法或微波消解处理后,采用电感耦合等离子体发射光谱法（ICP—OES）、原子吸收光谱法（AAS）和原子荧光光谱法（AFS）测定了其中Al、As、B、Ba、Ca、Cd、Co、cr、Cu、Fe、Hg、K、Mg、Mn、Mo、Na、Ni、P、Pb、Rb、S、Se和zn共23种矿质元素的含量,,并采用高效液相色谱法（HPLC）和荧光分光光度法测定了其中维生素B．,烟酸,烟酰胺,维生素B。和维生素B：的含量。另外,还研究了经水淘洗后这3种类型大米中矿质元素和B族维生素含量的损失情况。结果表明,矿质元素和B族维生素含量呈现糙米,胚芽米,精白米由高到低的基本特征,淘洗可使各种矿质元素和B族维生素产生不同程度的损失,其中精白米中维生素B．经水淘洗后已损失殆尽。3种类型大米中cd、Cu、Mo、Ni、S、Se、Zn等元素含量差异相对较小,并且淘洗对Mo、S元素含量几乎没有影响,而cd、cu元素含量经水淘洗后反而略有增加。     

Atomabsorptionsspektrometrie mit verdampfung fester Proben durch laserstrahlung—II. Analytische anwendungen

The use of a pulsed neodymium laser permits the direct analysis of solids (metallic and non-metallic) that cannot be analyzed by flame or oven AAS without preparation of the specimen. Microgram quantities are vaporized and partly atomized by the focused laser radiation. AAS techniques are used to investigate the freely expanding vapour of the sample by space and time resolution. The analytical application of this procedure is demonstrated by the determination of the trace constituents Cu, Mn, Mg, Fe, Zn and Si in aluminium and of Cu and Mn in steel.The analytical capability of this method is compared to other AAS techniques. The relative detection limits of ～ 10^?6 g g^?1 for Cu, Mn and Mg in aluminium agree with results obtained on similar samples using flame AAS. The absolute detection limits of ～ 10^?10 to 10^?11 g for these elements approach the values obtained in furnace AAS. The precision is limited by fluctuations in the laser evaporation and in the expansion of the sample vapour.     

The determination of wear metals in used lubricating oils by flame atomic absorption spectrometry using sulphanilic acid as ashing agent

A simple and reliable ashing procedure is proposed for the preparation of used lubricating oil samples for the determination of calcium, magnesium, zinc, iron, chromium and nickel by flame atomic absorption spectrometry. Sulphanilic acid was added to oil samples and the mixture coked and the coke ashed at 550 degrees C. The solutions of the ash were analysed by flame AAS for the metals. The release of calcium, zinc, iron and chromium was improved by the addition of sulphanilic acid to samples. The relative standard deviations of metal concentration results in the initial oil samples were 1.5% for Ca (1500 mg l(-1) level), 0.3% for Mg (100 mg l(-1) level), 3.1% for Zn (1500 mg l(-1) level), 0.7% for Fe (500 mg l(-1) level), 0.02% for Cr (50 mg l(-1) level) and 0.002% for Ni (10 mg l(-1) level). The optimum sample size for efficient metal release was 20 g while the optimum sulphanilic acid to oil ratio was 0.05 g per gram of oil for Zn and Cr and 0.10 g for Ca and Fe. Results obtained by this procedure were highly reproducible and comparable with those obtained for the same samples using standard procedures.     

Pure graphite as a reference material for the determination of trace elements — an interlaboratory collaborative study

Seven synthetic graphite powders of different grade of purity were analyzed by means of INAA, WDXRF, EDXRF, DC-OES directly and using ICP-MS, ICP-OES, ETAAS and FAAS in combination with various sample preparation techniques. On the basis of a statistical evaluation of the results obtained, for the trace elements Al, Ca, Cr, Cu, Fe, Mn and Ni, reference values were established and, for the elements As, Co, Mg, Mo, Pb, Sb, Si, Sr, Ti, V, Zn and Zr, informative values are given. The analyzed reference materials are commercially available.     

Flame AAS determination of dopants and trace metal impurities in single crystals of potassium titanylphosphate

A flame AAS method is used for the determination of dopants and impurities in potassium titanylphosphate (KTP) single crystals. Sample digestion using sulphuric acid and hydrofluoric acid is proposed as being the most appropriate procedure. The effect of major and minor components in the sample solution on the analytical signal is studied. The content of the dopants Cr, Mn and Ni (at a level of about 1 mg g(-1)) as well as the content of the impurities Fe, Na, Mg, W and Al (from 4 mug g(-1), depending on the trace metal) in the KTP single crystals is determined. The precision of the method is characterized by a relative standard deviation of 3-10%. The accuracy is checked by comparison with ICP-AES data for the trace element content in the KTP single crystals.     

Determination of Fe,Nb and Si in titanium (IV) oxide white pigments by AAS using multivariate linear calibration methods

Models for the quantitative determination of Fe, Nb and Si in titanium (IV) oxide white pigments by flame atomic absorption spectrometry (AAS) are described. For the models two multivariate linear calibration techniques have been used: principal component regression (PCR) and partial least squares (PLS1). Absorbances measured at wavelengths for elements present in solution have been considered as independent (x) variables, while the concentrations of elements (or their oxide) to be determined have been taken as dependent (y) variables. The results obtained by the models do not differ significantly (alpha=0.05) from those achieved by the XRF method checked in advance by another independent method, the neutron activation analysis (NAA).     

AAS multielement analysis of strontium and barium salts after preconcentration by precipitation of the matrix as nitrates

A method is described for the preconcentration and AAS-determination of trace elements such as Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, In, K, Mg, Mn, Na, Ni, Pd, Tl and Zn in high-purity strontium and barium nitrate and chloride. For that purpose the main constituents Sr or Ba are precipitated as nitrates by simple evaporation of the diluted nitric acid sample solutions. The solubility of Sr and Ba nitrate in the resulting concentrated HNO₃ is so small that the preconcentrated traces can be determined without interference from the matrix using the “injection method” in the flame AAS determination. For most of the investigated elements the recovery is about 95% (Hg ～ 50%, Cr ～ 80%); the relative standard deviation (N = 10, trace contents of the sample 0.2…5 ppm) in general is about 0.05. The detection limits (3σ, N = 25) were found to be between 1 and 0.01 ppm depending on the AAS sensitivity of the elements.     

Flame AAS/flame AES for trace determination in fresh and used lubricating oils with sample introduction by hydraulic high-pressure nebulization

In hydraulic high-pressure nebulization (HHPN) an aerosol is produced by means of an HPLC-pump and a special nebulization nozzle, applying a pressure of about 200 bar. This spray technique has been employed for sample introduction of mineral oil samples in flame atomic absorption/flame emission spectrometry. The determination of the trace elements Al, Cr, Cu, Fe, K, Na, Ni, Pb, Si and V has been investigated. Viscosity hardly acts upon the sensitivity of the determination, thereby avoiding a time consuming dilution of oil samples. By means of two interconnecting sampling valves a calibration method based on the standard addition technique can be performed which is both simple and easy to carry out. In samples of used oils, results for Cu and Pb equalled those of XRF-analysis. Regarding Fe traces, data obtained from AAS and XRF measurement correlate. In comparison with sample uptake by pneumatic nebulization, which is restricted to diluted oil samples, detection limits decrease by a factor of 2 to 4, indicating the dilution required in pneumatic nebulization.     

Flame AAS/flame AES for trace determination in fresh and used lubricating oils with sample introduction by hydraulic high-pressure nebulization

In hydraulic high-pressure nebulization (HHPN) an aerosol is produced by means of an HPLC-pump and a special nebulization nozzle, applying a pressure of about 200 bar. This spray technique has been employed for sample introduction of mineral oil samples in flame atomic absorption/flame emission spectrometry. The determination of the trace elements Al, Cr, Cu, Fe, K, Na, Ni, Pb, Si and V has been investigated. Viscosity hardly acts upon the sensitivity of the determination, thereby avoiding a time consuming dilution of oil samples. By means of two interconnecting sampling valves a calibration method based on the standard addition technique can be performed which is both simple and easy to carry out. In samples of used oils, results for Cu and Pb equalled those of XRF-analysis. Regarding Fe traces, data obtained from AAS and XRF measurement correlate. In comparison with sample uptake by pneumatic nebulization, which is restricted to diluted oil samples, detection limits decrease by a factor of 2 to 4, indicating the dilution required in pneumatic nebulization.     

Development of a certified reference material (NMIJ CRM 7505-a) for the determination of trace elements in tea leaves

A certified reference material (CRM) for trace elements in tea leaves has been developed in National Metrology Institute of Japan (NMIJ). The CRM was provided as a dry powder (<90 μm) after frozen pulverization of washed and dried fresh tea leaves from a tea plant farm in Shizuoka Prefecture, Japan. Characterization of the property value for each element was carried out exclusively by NMIJ with at least two independent analytical methods, including inductively coupled plasma mass spectrometry (ICP-MS), high-resolution (HR-) ICP-MS, isotope-dilution (ID-) ICP-MS, inductively coupled plasma optical emission spectrometry (ICP-OES), graphite-furnace atomic-absorption spectrometry (GF-AAS) and flame atomic-absorption spectrometry (FAAS). Property values were provided for 19 elements (Ca, K, Mg, P, Al, B, Ba, Cd, Cu, Fe, Li, Mn, Na, Ni, Pb, Rb, Sr, Zn and Co) and informative values for 18 elements (Ti, V, Cr, Y, and all of the lanthanides, except for Pm whose isotopes are exclusively radioactive). The concentration ranges of property values and informative values were from 1.59% (mass) of K to 0.0139 mg kg(-1) of Cd and from 0.6 mg kg(-1) of Ti to 0.0014 mg kg(-1) of Lu, respectively. Combined relatively standard uncertainties of the property values were estimated by considering the uncertainties of the homogeneity, analytical methods, characterization, calibration standard, and dry-mass correction factor. The range of the relative combined standard uncertainties was from 1.5% of Mg and K to 4.1% of Cd.     

Determination of trace elements in olive oil by ICP-AES and ETA-AAS: A pilot study on the geographical characterization

The determination of trace elements in edible oils is important because of both the metabolic role of metals and possibilities for adulteration detection and oil characterization.The most commonly used techniques for the determination of metals in oil samples are inductively coupled plasma atomic emission spectrometry (ICP-AES) and atomic absorption spectrometry (AAS). For this study, a microwave assisted decomposition of the olive oil in closed vessels using a mixture of nitric acid and hydrogen peroxide was applied as sample preparation.The low achievable LODs enable the determination by ICP-AES of even very low concentrations of most elements of interest. The proposed ICP-AES method permits the determination of Ca, Fe, Mg, Na, and Zn in olive oils. Elements present in small amounts (Al, Co, Cu, K, Mn, Ni) were measured by ETA-AAS in the same sample digest. The concentrations of Al, Co, Cu, K, Mn, and Ni were in the range from 0.15 to 1.5 μg/g and differ according to the geographical origin of the oils. For the amounts of Fe, Mg, Na, and Zn in the samples, no significant differences according to the geographical origin of the oils could be observed, the mean concentrations being 15.31, 3.26, 33.10, and 3.39 μg/g, respectively. The Ca content varies in the range of 1.3 to 9.0 μg/g.The dependency of the trace elemental content of olive oils on their geographical origin can be used for their local characterization.     

Pure graphite as a reference material for the determination of trace elements — an interlaboratory collaborative study

 Seven synthetic graphite powders of different grade of purity were analyzed by means of INAA, WDXRF, EDXRF, DC-OES directly and using ICP-MS, ICP-OES, ETAAS and FAAS in combination with various sample preparation techniques. On the basis of a statistical evaluation of the results obtained, for the trace elements Al, Ca, Cr, Cu, Fe, Mn and Ni, reference values were established and, for the elements As, Co, Mg, Mo, Pb, Sb, Si, Sr, Ti, V, Zn and Zr, informative values are given. The analyzed reference materials are commercially available. Received: 12 February 1996/Revised:27 March 1996/Accepted:2 April 1996     

A comparative study of standards for determinations of trace wear metals in jet engine oils

The feasibility of using acid-treated metal powder standards for the determination of trace wear metals in spent jet engine oils is evaluated. The addition of 2:3:3 (v/v/v) HF—HCl—HNO₃ mixture to used lubricating oils did not cause any statistically reliable differences from results obtained with organometallic standards. Two sets of six correlation samples, one set being acid-treated, were analyzed for Cu, Cr, Mg, Fe, Mo and V by flame atomic absorption and flame atomic fluorescence spectrometry against each set of standards.     

Characterization of the chemical composition of archaeological glass finds from South-Eastern Bulgaria using PIXE, PIGE and ICP-AES

Using PIXE (proton induced X-ray emission), PIGE (proton induced gamma emission) and ICP-AES (inductively coupled plasma-atomic emission spectroscopy) the concentrations of the 24 elements Al, As, Ba, Br, Ca, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Pb, Rb, S, Sb, Si, Sn, Sr, Ti, Zn and Zr in 53 archaeological glass samples from South-Eastern Bulgaria, were determined. The glasses are dated from the 1st to 6th century AD. The analytical data showed the samples to be typical soda-lime-silica glass, with natron as flux. A rather broad range of aluminium, titanium and iron impurities was found, with a tendency for more impure glass in the later periods. The decolouring agents were antimony and manganese oxides, with Sb prevailing in earlier, and Mn in later glass.     

A new approach for determination of crustal and trace elements in airborne particulate matter

An ICP-OES procedure was developed for fast and accurate determination of various crustal (Al, Ca, Fe, Mg, Si) and trace elements (Ba, Cu, Mn, Na, K, Sr, Ti, Zn) in airborne particulate matter. The method is based on a preliminary treatment of the aerosol samples with a mixture of nitric acid and hydrogen peroxide at elevated temperature leading to a mineralization of the organic sampling substrate, dissolution of soluble material and homogeneous suspension of the remaining non-soluble fraction. After dilution the derived slurry solutions were measured using ICP-OES. The reproducibility of analysis given as the relative standard deviation (% RSD) varied between 3.2 and 6.8% for bulk constituents such as Al, Ca, Fe, Mg and Si whereas values ranging from 3.5 to 9.1% were obtained for trace metals present with distinctly lower abundance in PM10 (e.g. Ba, Cu, Mn, Sr, Zn). The limits of detection (LOD) calculated as three times the standard deviation (3σ) of the signal derived from filter blank samples ranged from approximately 1?ng?m^?3 (Sr) to 71?ng?m^?3(Ca). The developed procedure was evaluated by comparing the obtained results with the findings derived for the same set of aerosol samples analyzed using a microwave procedure for sample dissolution with subsequent ICP-OES analysis. Finally the developed procedure was applied for the analysis of crustal and trace elements in PM10 samples collected at an urban site (Getreidemarkt, Vienna) and a rural site (Hartberg, Styria), in Austria. The concentrations of the investigated crustal elements varied between some hundred ng?m^?3 and few µg?m^?3 with highest concentrations for Fe and Si, distinctly reduced concentrations ranging from some ng?m^?3 (Sr) to more than hundred ng?m^?3 (K) were found for trace elements. Observed PM10 concentrations were found to be in accordance to literature findings from urban sites in central Europe.     

电感耦合等离子体发射光谱(ICP-OES)法同时测定活性炭中铝、钴、镉、铜、铁、镁、锰、钠、磷、硫10种元素

提出了使用ICP-OES同时测定活性炭中Al、Co、Cr、Cu、Fe、Mg、Mn、Na、P和S的分析方法。采用高氯酸和硝酸处理样品,以硝酸作为测定介质,在选定的仪器工作条件下直接测定。各元素的测定检出限为0.002～0.012μg/mL,相对标准偏差(RSD,n=6)为0.32%～1.83%。对样品进行加标回收试验,回收率在92.1%～108.4%之间。实验表明:方法不仅具有较高的灵敏度和较低的检出限,而且快速、准确,能够满足活性炭和以活性炭为载体的催化剂杂质元素分析的要求。     

The spectrographic determination of impurities in small amounts of radioactive graphite by the cathode layer technique

A modification of the cathode layer technique is suitable for the analysis of radioactive graphite using copper and cobalt as internal standards. The sample is ground with the internal standard mixture and introduced into a specially designed electrode which is burned in a d.c. arc. The cathode layer portion of the arc plasma is examined using a medium quartz spectrograph with photographic recording. The spectra are evaluated visually, by comparison with standard spectra, or by non-recording microphotometry using the “blackening separation” method. Using a 5-mg sample of graphite, the effective concentration range for Al, B, Ba, Be, Bi, Ca, Cr, Fe, Mg, Mn, Mo, Ni, Pb, Si, Sn, Ti and V is from 10 to 500 p.p.m. and the coefficient of variation for single exposures at the 100-p.p.m. level varies from 2 to 6% according to the element determined.