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Nine coppery alloys and five basaltic glasses have been quantitatively evaluated as the reference materials to employ in electron probe X-ray microanalysis. The optimum conditions for measurements were selected considering the dependence of intensity and detection limit on the conditions of the X-ray radiation excitation and analytical signal recording. The homogeneity of basaltic glasses and coppery alloys has been examined. The dependence of electron probe X-ray microanalysis accuracy on the homogeneity of reference materials was studied in the reference materials of coppery alloys.Six data sets comprising the average concentrations, standard deviations, relative standard deviations, confidence interval and the z-score of data quality were calculated for 50 control samples: 10 alloys, 14 glasses, 2 metals, 24 minerals and oxides. The average compositions of every control sample were derived in 8–16 analyses. The measured values were corrected for matrix effects applying the original program. These series of concentrations have been compared with each other and with the certified/recommended values using 2-pair selective Student's t-test.The results gained from both laboratory reference materials and certified glass reference materials show comparable accuracy. The quality of all available results complies with the “applied geochemistry” category of performance (2nd category). The laboratory reference materials give comparable accuracy to certified reference materials and can be used for calibrating microprobe techniques, as well as data quality control. The application of laboratory reference materials in microanalysis of silicate minerals and coppery alloys allows reliable analytical data to be acquired. The applications in mineralogy and metallurgy can be extended successfully to the targets when certified reference materials are not available. 相似文献
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Klaus Günther Alex von Bohlen Gerhard Paprott Reinhold Klockenkämper 《Fresenius' Journal of Analytical Chemistry》1992,342(4-5):444-448
Summary Total-reflection X-ray fluorescence (TXRF) and inductively coupled plasma mass spectrometry (ICP-MS) were used for the analysis of two biological reference materials. The quantifications were carried out after addition of one single standard element which serves as an internal standard in both cases. The results of TXRF analysis were good to satisfactory. The method is therefore suitable for fast multielement analysis, because it needs no special calibration specimens. The results of ICP-MS analysis are at least in the order of magnitude of the certified values. In some cases recoveries fit very well. For quantitative analysis, however, the use of the standard addition method or the calibration with external standards is required. 相似文献
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《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(9-10):1363-1372
X-ray fluorescence spectroscopy (XRF) is universally recognized as a non-destructive method for rapid and sequential, or simultaneous analysis of elemental composition of a material. The use of this technique for the direct determination of chemical elements in plant matrices has increased over the last few years.In the present study, a wavelength dispersive X-ray fluorescence (WDXRF) method for the quantitative analysis of some major elements (Na, Mg, Al, P, S, K, Ca), trace elements (Mn, Fe, Co, Zn, As) and non-essential elements (Sr, Pb) in vegetation specimens has been developed. The method uses a quick and easy sample preparation procedure since only drying, pulverizing and pressing of the samples are necessary. The calibration procedure was established by employing four plant reference materials and several synthetic cellulose calibrators spiked with appropriate amounts of analytes. Matrix effects were corrected employing the method of the influence coefficients on the basis of the computerized routine program linked to the equipment.Trueness of the experimental procedure was checked by using the standard reference material GBW07602 “Bush branches and leaves”. In general, good agreement was achieved between certified values and the measured ones with recoveries ranging from 94% to 107%. Moreover, quality parameters, including repeatability and reproducibility of the developed method, were also evaluated.On the whole, from results obtained, WDXRF method proposed prove to be good and effective tool for environmental investigation and quality control processes in vegetation specimens. 相似文献
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T. Shinonaga F. Esaka M. Magara D. Klose D. Donohue 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
The isotopic composition of single uranium and plutonium particles was measured with an inductively coupled plasma mass spectrometer (ICP-MS) and a thermal ionization mass spectrometer (TIMS). Particles deposited on a carbon planchet were first analyzed with an energy dispersive X-ray spectrometer (EDX) attached to a scanning electron microscope (SEM) and then transferred on to a silicon wafer using a manipulator. The particle on the silicon wafer was dissolved with nitric acid and the isotopic ratios of U and Pu were measured with ICP-MS and TIMS. The results obtained by both methods for particles of certified reference materials showed good agreement with the certified values within the expected uncertainty. The measurement uncertainties obtained in this study were similar for both mass spectrometric methods. This study was performed to establish the method of particle analysis with SEM, EDX, the particle manipulation and chemical preparation technique, and the measurement of isotopic ratios of U and Pu in a single particle by mass spectrometry. 相似文献
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Josef Kratochvíla Bedřich Friedecký Marek Budina Ilona Šperlingová 《Accreditation and quality assurance》2007,12(3-4):146-150
In this paper, the creation of a certified reference material for urinary creatinine is described. We used the Jaffe method
and HPLC method for establishment of the certified value. Homogeneity tests are also described. We obtained material with
sufficient homogeneity, stability, and with certified value (expanded uncertainty, k=2 for CI 95%) (7.77±0.27) mmol·L−1. This material was consequently used for the interlaboratory comparison (EQA Czech Republic for clinical chemistry). Twenty-nine
percent of the participants obtained measurement results within the interval of the certified value ± expanded uncertainty,
while 85% of the participants obtained values inside the interval of the certified value ± target measurement uncertainty.
Direct use of the certified reference materials for method evaluation in EQA programs means a significant advance for monitoring
and documentation traceability of results in routine measurements. 相似文献
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《Spectrochimica Acta Part B: Atomic Spectroscopy》2001,56(11):2095-2106
Three different techniques, energy dispersive X-ray fluorescence, total reflection X-ray fluorescence and particle induced X-ray emission were used to initiate an evaluation program on quality assurance (QA) procedures applied to X-ray spectrometry for chemical analysis. The use of standard methodologies to assure the statistical control of measurement data is the main objective of this work. Certified Reference Materials were used and up to 15 certified elements were analyzed to carry out the QA procedures. For the internal quality control, z-scores were calculated and control charts were produced. The plotted elemental data illustrate statistically controlled methodologies for the majority of the determinations. Even the cases where the control charts exhibit values out of control limits, the z-scores are below 3 in absolute value, indicating satisfactory results. Concerning external quality control the statistical methods applied showed that the results obtained for the three techniques are comparable, although some significant differences occur, mainly due to sample preparation. Therefore, the techniques are traceable to certified reference materials and the data gathered so far, enable to initiate a database for QA procedures. 相似文献
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The electrodepositons of Te, Bi, Ni, Sb and Au from aqueous solution of pH = 1 on the cathode surface have been studied for X-ray fluorescence analysis (XRF). A special holder for a copper electrode has been constructed to perform the electrodeposition process on only one side of the electrode. After electrolysis, the copper electrode can be easily removed from the holder; after rinsing it with water and drying it can be analyzed by XRF. The proposed method of sample preparation and preconcentration of Te, Bi, Ni, Sb, Au provides suitable samples which are devoid of the negative and undesirable effects of XRF analysis, such as particle size and matrix effects. The influence of time on the deposition yield has been examined. The method of preconcentration is efficient. The inhomogeneity of the prepared specimens has been studied using internal standard method. The calibration is based on using synthetic standards, certified reference materials and standard addition method. The best results are achieved by the standard addition method. The agreement between results obtained with XRF analysis and certified values is satisfactory and indicates the usefulness of the proposed method for determination of Te, Bi, Ni, Sb and Au in anode slime. 相似文献
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介绍铝合金化学成分标准物质的研制过程。采用中频感应电炉熔炼法制备了铝合金化学成分标准物质候选物,并对标准物质候选物的均匀性和稳定性进行了考察。选择6家具有资质的实验室对研制的标准物质中各化学成分进行协作定值,并对各元素定值的不确定度进行评定。结果表明,在95%的置信区间内标准物质均匀性良好,经过13个月稳定性考察试验,标准物质稳定性良好。Si,Fe,Cu,Mn,Mg,Ti,Cd,V,Zr,B,Sn,Zn的定值结果分别为0.013 8%,0.012 5%,2.868%,0.185%,0.014 0%,0.082 8%,0.041 7%,0.032 9%,0.031 4%,0.003 8%,0.003 4%,0.025 6%,定值结果的相对扩展不确定度为1.4%~9.0%(k=2)。研制的标准物质达到相关技术要求,可用于该类铝合金材料的质量控制。 相似文献
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Sheila Alves Margarida Maria Correia dos Santos Maria Ascensão Trancoso 《Accreditation and quality assurance》2009,14(2):87-93
In this work estimation of measurement uncertainties associated with the total metal content in soils was done by an intralaboratory
approach based on method validation and quality control data, and using two certified reference materials (CRM). CRM and soil
samples were analyzed following procedures based on the methods that are applied to silicate materials. All elements were
determined by atomic absorption spectrometry following a quality assurance program previously established. Quality control
actions were implemented in order to provide reliable data. The precision under within-laboratory reproducibility conditions
was estimated from triplicate analysis. The trueness component was determined as recovery of the analyte from CRMs: soil sample,
SO-2 and river clay sediment, LGC 6139. Combined measurement uncertainty was expressed in terms of precision and recovery
uncertainties and the later further split on CRM replicate analysis and uncertainty of the certified value components. The
results obtained are critically discussed on the basis of the different contributions. For the selection of the reference
material, the CRM dependent terms are critically compared in order to fulfill specific requirements.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Liuxing Feng Liandi Ma Jun Wang Hai Lu 《Analytical and bioanalytical chemistry》2010,396(8):3051-3057
Two reference materials, at relatively low and high concentrations (GBW08404 and GBW08405), for analysis of the mass fractions
of Cd, Cr, Hg and Pb in polypropylene were developed. The reference materials were prepared by doping blank polypropylene
base material with Cd, Cr, Hg and Pb in the form of oxides, salts or pigments. Homogeneity and stability studies were performed
by inductively coupled plasma mass spectrometry. The certification of the four analytes was carried out by isotope-dilution
mass spectrometry (IDMS) with microwave-assisted digestion. Combined uncertainties were calculated from the IDMS uncertainty
evaluation budget and the uncertainty of the homogeneity. The mass fractions of Cd, Cr, Hg and Pb of the two certified reference
materials (CRMs) were from 8 to 1,000 mg kg−1. The two samples were also used in an interlaboratory comparison scheme in which National Institute of Metrology, China,
National Metrological Institute of Japan and Korea Research Institute of Standards and Science participated. The agreement
of the comparison results proved that the certification procedure of the CRMs is valid and that the certified values of Cd,
Cr, Hg and Pb are accurate and reliable. 相似文献
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XRF检验标准物质中痕量元素的匀性 总被引:4,自引:0,他引:4
本文讨论了用X射线荧光光谱检验标准物质中痕量元素的均匀性时,可根据峰和背景强度确定能否用XRF进行检验,以及相应于一定精度度要求的浓度下限(可检浓度),并以大米和岩石标准物质为例,计算了C-的可检浓度。还指出,作为均匀性检验量应采用浓度或净强度,尤其是对于痕量元素,最后说明了样品基体对可检浓度和最小样品量的影响。 相似文献
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采用镁砂标准样品作为校准样品,建立了熔融制样X射线荧光光谱法测定镁砂中MgO,Al2O3,SiO2,CaO,P2O5,Fe2O3的方法。采用熔融法为样品片和校准片的制备方法,选择四硼酸锂-偏硼酸锂(67+33)为助熔剂,1.00mL LiBr溶液为脱模剂,熔融温度为1 100℃,熔融时间20min。对镁砂样品测定的相对标准偏差(RSD)小于3%,对不同镁砂标准样品进行测定,方法的测定结果与认证值相吻合。 相似文献
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S. Duta 《Accreditation and quality assurance》2000,5(8):339-345
The objective of quality assurance programme for spectrochemical measurements is to reduce the measurement errors to accepted
limits. Reference materials are being widely used as measurement standards in the fields of industrial production, environmental
protection and clinical chemistry, and are playing an important role in ensuring the quality of measurement results. This
paper presents some aspects, practices and examples of the activity of the Reference Materials Laboratory of the National
Institute of Metrology, Bucharest, in the field of spectrochemical measurements. An attempt to describe the role and use of
reliable certified reference materials to ensure the quality of spectrochemical measurements is presented. A short review
of the locally available certified reference materials used in spectrochemical measurements is given. The use of reference
materials data in estimating the measurement uncertainty is discussed. An interlaboratory comparison, recently organized in
Romania, is also presented as a useful response to the need for quality assurance of spectrochemical results.
Received: 20 March 1999 / Accepted: 25 February 2000 相似文献
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