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1.
The International Measurement Evaluation Programme (IMEP) is an interlaboratory comparison scheme founded, owned and co-ordinated by the Institute for Reference Materials and Measurements (IRMM) since 1988. IMEP-14, for the first time in the series, is focusing on trace elements in sediment. Reference values for ten elements stating total concentrations and expanded uncertainties according to GUM were established. In total, 239 laboratories from 43 countries in five continents participated in the comparison, and the degree of equivalence between the results from the laboratories and the reference values is presented graphically. Identical samples were distributed to nine National Measurement Institutes within the frame of the CCQM-P15 pilot study. Participation in the IMEP-14 interlaboratory comparison was offered to laboratories in the EU new member states and acceding countries according to the IRMMs Metrology in Chemistry support programme for EU new member states and acceding countries.This revised version was published online in August 2004 with corrections to text especially to the Discussion section. 相似文献
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A. Lamberty J. Savory J. R. Moody P. De Bièvre K. J. R. Rosman J. W. Gramlich 《Accreditation and quality assurance》1998,3(11):447-458
The aim of the International Measurement Evaluation Programme (IMEP) is to give an objective picture of state-of-the-practice analytical measurements by comparing them to a reference value obtained by a primary method of measurement. The referencevalue is therefore as traceable to the SI system of measurements as can presently be achieved and is independent of human or political decisions. Thus a large scale field test is made to achieve (international) comparability of measurements by comparing them with an independent metrologically established value. In the fourth measurement round, IMEP-4, three trace elements, Li, Cu and Zn, at three different levels in (bovine) serum were measured by about 12 participating laboratories using their routine methods. The (coded) results are graphically reported and compared to certified reference values established by an isotope-specific method, isotope dilution mass spectrometry, defined as a primary method of measurement by the Consultative Committee on Amount of Substance. Results indicate a spread of more than ±50%, asymmetrically distributed around the reference value with its own uncertainty range, although the self-declared accuracy of the laboratories was 5–10%. Self-assessment by participants of their analytical capabilities does not show a high correlation between self-rating ("more experienced" or "less experienced") and actual performance. In the way they have been applied, all methods seem to produce results of approximately the same quality. 相似文献
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U. Örnemark L. Van Nevel P. D. P. Taylor P. Robouch P. De Bièvre A. Uldall M. Loikkanen M. M. Müller J.-C. Libeer H. Steensland K. Hellsing A. Squirrell L. A. Penberthy D. Schiel T. Tamberg T. Walczyk J. W. H. Lam 《Accreditation and quality assurance》1999,4(11):463-472
In the seventh round of the Institute for Reference Materials and Measurements' International Measurement Evaluation Programme,
277 clinical laboratories from 17 countries participated. The measurands consisted of inorganic components, present at minor
and trace level, in a human liquid serum. Results for calcium, chloride, copper, magnesium, sodium, selenium and zinc are
reported and are compared to reference values established mainly by isotope dilution mass spectrometry and neutron-activation
analysis. The overall conclusion is that routine measurements of total concentrations of the components by clinical laboratories
are of high quality. The fraction of significant errors is small (0.5%) and the self-declared uncertainty values are generally
fairly realistic. Results are further commented on with respect to the recent development in metrology in chemistry.
Received: 5 March 1999 / Accepted: 24 July 1999 相似文献
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J. Vogl C. R. Quétel M. Ostermann I. Papadakis L. Van Nevel P. D. P. Taylor 《Accreditation and quality assurance》2000,5(7):272-279
The present paper describes the contribution of the Institute for Reference Materials and Measurements to the certification
of B, Cd, Mg, Pb, Rb, Sr, and U amount contents in a natural water sample, in round 9 of the International Measurement Evaluation
Programme (IMEP-9). The analytical procedure to establish the reference values for B, Cd, Mg, Pb, Rb, Sr, and U amount contents
was based on isotope dilution inductively coupled plasma-mass spectrometry used as a primary method of measurement. Applying
this procedure reference values, traceable to the SI, were obtained for the natural water sample of IMEP-9. For each of the
certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties
according to ISO and EURACHEM guidelines. The measurement procedures, as well as the uncertainty calculations are described
for all seven elements mentioned above. In order to keep the whole certification process transparent and so traceable, the
preparations of various reagents and materials as well as the sample treatment and blending, the measurements themselves,
and finally the data treatment are described in detail. Explanations focus on Pb as a representative example. The total uncertainties
(relative) obtained were less than 2% for all investigated elements at amount contents in the pmol/kg up to the high μmol/kg
range, corresponding to low μg/kg and mg/kg levels.
Received: 21 October 1999 / Accepted: 29 January 2000 相似文献
6.
Ines BaerJohannes van de Kreeke Thomas Peter Josef LinsingerPiotr Robouch Fernando Cordeiro RaposoBeatriz de la Calle 《Trends in analytical chemistry : TRAC》2011,30(2):313-323
The International Measurement Evaluation Program (IMEP) organized the IMEP-24 interlaboratory comparison after reports in the media about high levels of lead in toys. The aim of this comparison was to verify the laboratories’ capacity to evaluate trace-element levels in a possible toy-like material according to the European Standard EN 71-3:1994. As test material, it used a former certified reference material containing levels of antimony, arsenic, barium, cadmium, chromium, mercury, lead and selenium around the limits set in the standard.Four expert laboratories confirmed the reference values (Xref) for all elements but Hg, and established a reference value for Hg. The scatter of the results reported by the participants was large, as expected, but showed a close to normal distribution around the reference values for five of the eight trace elements. The spread of results was mainly attributed to sampling and sample preparation.One major issue observed in this exercise was the lack of legislative rules about how to report the result, or, more specifically, the use of the analytical correction, which was introduced in EN 71-3:1994 to achieve consistent interpretation of results and which is to be applied when values are equal to or above the maximum limits set in the standard. Its application by the participants was very inconsistent and led to problems in their evaluation. There is clearly a need for clarification and for more formal regulations with regard to result reporting in order to minimize the risk of confusion.Participants were also asked to give their opinion with regard to the acceptability of the test material for the market. The majority correctly considered the material as non-compliant. However, almost one-third incorrectly assessed the material as compliant. 相似文献
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Ines BaerJohannes van de Kreeke Thomas Peter Josef LinsingerPiotr Robouch Fernando Cordeiro RaposoBeatriz de la Calle 《Trends in analytical chemistry : TRAC》2011,30(7):1177
The International Measurement Evaluation Program (IMEP) organised the IMEP-24 interlaboratory comparison after reports in the media about high levels of lead in toys. The aim of this comparison was to verify the laboratories’ capacity to evaluate trace-element levels in a possible toy-like material according to the European Standard EN 71-3:1994. As test material, it used a former certified reference material containing levels of antimony, arsenic, barium, cadmium, chromium, mercury, lead and selenium around the limits set in the standard.Four expert laboratories confirmed the reference values (Xref) for all elements but Hg, and established a reference value for Hg. The scatter of the results reported by the participants was large, as expected, but showed a close to normal distribution around the reference values for five of the eight trace elements. The spread of results was mainly attributed to sampling and sample preparation.One major issue observed in this exercise was the lack of legislative rules about how to report the result, or, more specifically, the use of the analytical correction, which was introduced in EN 71-3:1994 to achieve consistent interpretation of results and which is to be applied when values are equal to or above the maximum limits set in the standard. Its application by the participants was very inconsistent and led to problems in their evaluation. There is clearly a need for clarification and for more formal regulations with regard to result reporting in order to minimise the risk of confusion.Participants were also asked to give their opinion with regard to the acceptability of the test material for the market. The majority correctly considered the material as non-compliant. However, almost one-third incorrectly assessed the material as compliant. 相似文献
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Nørgaard JV Valkiers S Van Nevel L Vendelbo E Papadakis I Bréas O Taylor PD 《Analytical and bioanalytical chemistry》2002,374(6):1147-1154
In IMEP-8, two samples of high purity CO(2)(g), with different carbon and oxygen isotope ratios were distributed to 27 participants, originating from 14 countries and from various isotopic measurement domains (geochemistry, atmospheric and food chemistry), but particularly set up for food laboratories. In total 19 laboratories reported results. The outcome of this comparison exercise shows that the laboratories reported carbon and oxygen isotope results in good agreement with the reference values across the domains. The reported results for delta(13)C(VPDB) (carbon) for both materials are within 1 per thousand. However, for the reported results of delta(18)O(VPDB) (oxygen) for both materials the overall spread of the reported results is about 11 per thousand. Within this spread two distinct groups of participants can be identified, where the results within each group vary about 2 per thousand. The latter seems to be caused by calculation errors by participants of the reporting delta(18)O(VPDB) values. As requested, participants also reported the isotope amount ratio for carbon and oxygen in the CO(2) samples. For carbon, all reported results for both materials agree with the isotope ratio value, which can be traced back to the value reported by Craig. For oxygen, all results are in good agreement and deviate by a maximum of 0.5% from the reference values measured at IRMM. Work carried out indicates the carbon isotope ratio, for both samples IMEP-8A and IMEP-8B, differ from those reported by Craig by as much as 1.2%. In the case of oxygen, this deviation is far smaller. Both data sets, i.e. the one realised by Craig and the one realised at IRMM, demonstrate traceability to SI. It is clear that both values significantly disagree. 相似文献
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L. Van Nevel Philip D. P. Taylor Ulf Örnemark Paul De Bièvre 《Accreditation and quality assurance》1998,3(11):444-446
For the 6th measurement round of the International Measurement Evaluation Programme, "Trace Elements in Water", pictures
are now available in electronic form displaying the results and answers from participating laboratories, against reference
values for the amount content anchored in the SI system via Primary Methods of Measurement.
Received: 30 May 1998 · Accepted: 2 June 1998 相似文献
10.
The International Measurement Evaluation Programme (IMEP) attempts to shed light on the current state of the practice in
chemical measurements. The main tool, which assists this attempt and also differentiates IMEP from similar projects, is the
establishment of SI-traceable reference ranges (where possible) for the elements offered for measurement to the participants
for every IMEP round. The Institute for Reference Materials and Measurements (IRMM), as the founder and co-ordinator of IMEP
has the responsibility of establishing the SI-traceable reference ranges. This is a large task that requires knowledge, skill
and resources. IRMM collaborates with a network of reference laboratories in order to achieve the establishment of SI-traceable
reference ranges in a transparent and reliable way. The IMEP reference laboratories must have demonstrated experience and
have a proven and successful record in the use of primary methods of measurements (mainly isotope dilution mass spectrometry)
and the application of uncertainty evaluation according to ISO/BIPM guidelines. In IMEP-9 "trace elements in water", results
from 7 reference laboratories (including IRMM) were combined by IRMM to establish SI-traceable ranges for the 15 elements,
which were then offered for measurement to the 200 participants worldwide. This paper does not discuss the individual contribution
of the reference laboratories (this could be the subject of individual papers) but describes the procedures and criteria used
in order to establish the reference ranges for the IMEP-9 samples by combining the individual contributions. All results submitted
to IRMM are included, so as to make this publication as realistic as possible.
Received: 31 December 1999 / Accepted: 7 March 2000 相似文献
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同位素稀释质谱法(IDMS)是微量、痕量元素量值测量的准确方法之一[1,2] .已应用到环保、生化等领域中,在痕量、超痕量化学分析中起着重要的作用[3~5] .欧共体联合研究中心标准物质与测量研究院(EC-JRC-IRMM)从1988年开始专门组织了国际测量评估计划(IMEP).该计划已实施多次,每次都有来自不同国家和地区的200多个实验室参加比对测量.IMEP国际比对样品中无机元素的标准值大都采用 IDMS 方法测得 [6].本实验室应 EC-JRC-IRMM 的邀请参加了 IMEP-9 国际比对标准样品的定值工作.本工作采用 IDMS 对 IMEP-9 天然水样品中的镁进行了测定研究.针对样品中 Mg 含量较低, 试剂、环境等因素的污染,轻质量数元素在质谱分析中磁场不易稳定、分馏效应影响较大等问题进行了大量实验研究,测得数据的不确定度为 0.25%,已被 EC-JRC-IRM M 作为 IMEP-9 国际比对标样的标准值[7]. 1 实验部分 1.1 仪器与试剂 Finnigan-MAT261 热表面电离同位素质谱计;25Mg 浓缩同位素(中国原子能科学研究院);氧化镁:优级纯;盐酸、水:经石英亚沸蒸馏提纯. 相似文献
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Ioannis Papadakis Lutgart Van Nevel Caroline Harper Yetunde Aregbe Philip D. P. Taylor 《Accreditation and quality assurance》2007,12(2):105-111
The International Measurement Evaluation Programme (IMEP) is an interlaboratory comparison scheme, founded, owned and co-ordinated
by the Institute for Reference Materials and Measurements (IRMM) since 1988. IMEP-12, for the fourth time in the series, focused
on trace elements in water and it was designed specifically to support European Commission directive 98/83/EC. Reference values
for the concentration of ten elements were established with expanded uncertainties according to GUM. In total, 348 laboratories
from 46 countries in five continents participated in the comparison and the degree of equivalence between the results of the
laboratories and the reference values is presented graphically. Samples from the same batch were distributed to ten laboratories
from European Countries, which represented their country in the framework of the EUROMET project 528. Participation in this
comparison was offered to the European Co-operation for Accreditation (EA) for participation of accredited laboratories from
all over Europe in the framework of the collaboration between IRMM and EA and to laboratories from the EU new member states
and acceding countries in the frame of IRMM’s ‘Metrology in Chemistry support program for EU new member states and acceding
countries.’ 相似文献
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K. H. Lieser P. Burba W. Calmano W. Dyck E. Heuss S. Sondermeyer 《Mikrochimica acta》1980,74(5-6):445-454
Summary Methods of discrimination between different chemical forms of trace elements in natural waters and for their separation are discussed and results given for their application to Rhine water. Various methods of trace element separation are presented: separation from sea-water by adsorption on activated carbon in presence of complexing agents, separation from mineral waters by use of the chelating cellulose exchanger Hyphan, separation of actinide elements by co-precipitation with barium sulphate, co-precipitation from waste water with hydrous ferric oxide and with ferric phosphate.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献
Trennung von Spurenelementen aus natürlichem Wasser und Abwässern
Zusammenfassung Methoden der Unterscheidung verschiedener chemischer Formen der Spurenelemente in natürlichen Wässern und ihre Trennung werden diskutiert und für Rheinwasser angewendet. Folgende Ergebnisse von Spurenelement-Trennungen werden beschrieben: Abtrennung aus Meerwasser durch Adsorption an Aktivkohle in Gegenwart von Komplexbildnern, Abtrennung aus Mineralwässern unter Verwendung des chelatbildenden Zelluloseaustauschers Hyphan, Abtrennung der Actinidenelemente MIV durch Mitfällung mit Bariumsulfat, Mitfällung mit Eisenhydroxid und Eisenphosphat aus Abwasser.
Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980. 相似文献
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I. Papadakis P. D. P. Taylor P. D. Bièvre 《Fresenius' Journal of Analytical Chemistry》1997,357(8):1020-1023
The certification measurement for the cadmium concentration in the samples as performed by Isotope Dilution (ID) using Inductively
Coupled Plasma Mass Spectrometry (ICP-MS) is described in framework of the International Measurement Evaluation Programme
(IMEP). By using a primary method of measurement (ID), making up a full uncertainty budget and using a sensitive technique
(ICP-MS), reference values traceable to SI can be obtained for this material.
The uncertainty budget is performed in accordance with the ISO and EURACHEM guides on uncertainty. A comparison is made with
certification results of other experienced laboratories also using primary methods where possible.
Received: 8 July 1996/Revised 26 August 1996/Accepted: 1 September 1996 相似文献
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A systematic study was undertaken in order to find out which of the most relevant elements can be determined in water under
normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized
water samples as well as natural water of different kind were used, brought to dryness by freeze-drying and irradiated in
quartz at a neutron flux of 1014 cm−2 s−1 for 1 day. The trace element content in quartz ampoules of different origin was determined separately. The following elements
are discussed in detail including possible interferences: As, Au, Br, Ca, Cd, Co, Cr, Cu, Eu, Fe, Hg, K, La, Mo, Na, Ni, Sb,
Sc, Se, U, Zn.
Presented at the Euroanalysis II Conference, Budapest, 25–30. Aug. 1975. 相似文献
18.
The contribution of the Institute for Reference Materials and Measurements to the certification of the B, Cd, Cu, Mg, and Pb content of a synthetic water sample used in Comparison 12 of the International Measurement Evaluation Programme (IMEP-12) is described. The aim of the IMEP programme is to demonstrate objectively the degree of equivalence and quality of chemical measurements of individual laboratories on the international scene by comparing them with reference ranges traceable to the SI (Système International d'Unités). IMEP is organized in support of European Union policies and helps to improve the traceability of values produced by field chemical measurement laboratories. The analytical procedure used to establish the reference values for the B, Cd, Cu, Mg, and Pb content of the IMEP-12 sample is based on inductively coupled plasma-isotope-dilution mass spectrometry (ICP-IDMS) applied as a primary method of measurement. The measurements performed for the IMEP-12 study are described in detail. Focus is on the element boron, which is particularly difficult to analyze by ICP-MS because of potential problems of low sensitivity, high mass discrimination, memory effects, and abundance sensitivity. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO (International Organization for Standardization) and Eurachem guidelines. For all investigated elements with concentrations in the low micro g kg(-1) and mg kg(-1) range (corresponding to pmol kg(-1) to the high micro mol kg(-1) level), SI-traceable reference values with relative expanded uncertainties ( k=2) of less than 2 % were obtained. 相似文献
19.
A. Chukka Reddy S. Janardhan C. Radhakrishna Murthy A. S. Nageswara Rao 《Radiation Physics and Chemistry》1999,56(5-6)
The method of elemental analysis based on the measurement of attenuation coefficient has been used to estimate the impurity introduced in a water matrix using a scintillation detector with a single channel analyser. For a 2% change in the mass attenuation coefficient the minimum detectable fractions of impurities were estimated to be of the order of 625–1250 μg/g for uranium and thorium compounds at photon energies 32.1 and 59.5 keV. 相似文献
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S. J. Yeh J. C. Wei C. N. Ke C. Y. Yang 《Journal of Radioanalytical and Nuclear Chemistry》1994,179(2):221-229
In order to assure the public health, simple and relibable analytical methods must be established for effective surveillance of polluted surface water. Since the pollutants in surface water are usually found at ultratrace levels, preconcentration is generally required to ensure the quality of the analytical results. An analytical procedure consisting of preconcentration using hydrous magnesium oxide followed by neutron activation analysis has been proposed and applied to the determinations of trace elements in surface water. 相似文献