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1.
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Wise SA Poster DL Kucklick JR Keller JM Vanderpol SS Sander LC Schantz MM 《Analytical and bioanalytical chemistry》2006,386(4):1153-1190
For the past 25 years the National Institute of Standards and Technology (NIST) has developed certified reference materials
(CRMs), known as standard reference materials (SRMs), for determination of organic contaminants in environmental matrices.
Assignment of certified concentrations has usually been based on combining results from two or more independent analytical
methods. The first-generation environmental-matrix SRMs were issued with certified concentrations for a limited number (5
to 10) of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Improvements in the analytical certification
approach significantly expanded the number and classes of contaminants determined. Environmental-matrix SRMs currently available
include air and diesel particulate matter, coal tar, marine and river sediment, mussel tissue, fish oil and tissue, and human
serum, with concentrations typically assigned for 50 to 90 organic contaminants, for example PAHs, nitro-substituted PAHs,
PCBs, chlorinated pesticides, and polybrominated diphenyl ethers (PBDEs).
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
3.
Olaf Rienitz Detlef Schiel Bernd Güttler Michael Koch Ulrich Borchers 《Accreditation and quality assurance》2007,12(12):615-622
Metrologically traceable reference values add an essential benefit to interlaboratory comparisons: unlike consensus values,
they can be used to establish national and international comparability. Furthermore, the participating laboratories obtain
a reliable and unbiased benchmark to check their results for accuracy. Usually, metrologically traceable reference values
are obtained by so-called primary methods which demand excessive efforts at great expense. Within the framework of two national drinking-water interlaboratory comparisons
(proficiency testing rounds), a new approach to provide metrologically traceable reference values was applied. It is solely
based on existing data which were collected during the comparison itself. Lead (Pb) measurements serve as an example to show
how metrologically traceable reference values were derived from the lead amount added during sample preparation and the amount
of lead already present in the drinking-water matrix used to prepare these samples. Within this approach, the matrix content
is calculated in a way similar to a standard addition experiment. An uncertainty budget for the reference value was set up
which describes the link to the corresponding SI units. Isotope dilution mass spectrometry (IDMS) as a primary method was
used to validate this approach in the case of cadmium, chromium, copper, lead, and nickel. 相似文献
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5.
K. Heydorn 《Accreditation and quality assurance》1998,3(3):111-114
Stability tests are carried out on candidate reference materials in order to ascertain that the certification values continue
to be valid a reasonable time after completion of the certification analysis. These tests are also used for recommending storage
conditions, as well as the duration of storage before certification values need be rechecked. BCR (Community Bureau of Reference)
reference materials do not normally have an expiry date, but rely on stability monitoring throughout the lifetime of the certified
material. The 1997 version of the BCR Guidelines for the production and certification of reference materials does, however,
take into account the necessity of limiting the validity of a certification, when degradation of the material during storage
cannot be ignored. This paper discusses an example of significant degradation taking place between the time of completion
of the certification analysis and the issue of a formal certificate. Various options are presented together with an account
of their influence on the certified values and their uncertainties.
Received: 3 October 1997 · Accepted: 3 November 1997 相似文献
6.
Yoshitaka Shimizu Yoko Ohte Xinnu Bao Satoko Otsuka Yuko Kitamaki Keiichiro Ishikawa Toshihide Ihara Kenji Kato 《Accreditation and quality assurance》2008,13(7):389-396
For accurate measurement of concentrations of substances by instrumental analysis, reliable calibration standards are needed.
In Japan, national reference materials are supplied under the national standards dissemination system named the Japan Calibration
Service System (JCSS). In JCSS, calibration standards for the analysis of environmental pollutants are supplied. For the traceability
to the SI of reference materials for calibration in JCSS, the National Metrology Institute of Japan (NMIJ) is developing high-purity
reference materials of volatile organic compounds (VOCs) as NMIJ CRMs. The freezing-point depression method, which has potential
as a primary method of measurement, is employed for the determination of property value. In this paper, a development scheme
of certified reference materials of high-purity VOCs is described.
Presented at BERM-11, October 2007, Tsukuba, Japan. 相似文献
7.
Two new marine sediment standard reference materials (SRMs) for the determination of organic contaminants 总被引:3,自引:0,他引:3
Wise SA Poster DL Schantz MM Kucklick JR Sander LC Lopez de Alda M Schubert P Parris RM Porter BJ 《Analytical and bioanalytical chemistry》2004,378(5):1251-1264
Two new marine sediment standard reference materials (SRMs), SRM 1941b Organics in Marine Sediment and SRM 1944 New York/New Jersey Waterway Sediment, have been recently issued by the National Institute of Standards and Technology (NIST) for the determination of organic contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, and chlorinated pesticides. Both sediment SRMs were analyzed using multiple analytical methods including gas chromatography/mass spectrometry (GC/MS) on columns with different selectivity, reversed-phase liquid chromatography with fluorescence detection (for PAHs only), and GC with electron capture detection (for PCBs and pesticides only). SRM 1941b has certified concentrations for 24 PAHs, 29 PCB congeners, and 7 pesticides, and SRM 1944 has certified concentrations for 24 PAHs, 29 PCB congeners, and 4 pesticides. Reference concentrations are also provided for an additional 58 (SRM 1941b) and 39 (SRM 1944) PAHs, PCB congeners, and pesticides. SRM 1944, which was collected from multiple sites within New York/New Jersey coastal waterways, has contaminant concentrations that are generally a factor of 10–20 greater than SRM 1941b, which was collected in the Baltimore (Maryland) harbor. These two SRMs represent the most extensively characterized marine sediment certified reference materials available for the determination of organic contaminants.Electronic Supplementary Material Supplementary material is available in the online version of this article at . A link in the frame on the left on that page takes you directly to the supplementary material. 相似文献
8.
In order to control the quality of trimethyl‐lead determination in urban dust, the Standards, Measurements and Testing Programme (formerly BCR) of the European Commission organized interlaboratory studies of which the final aim was to certify a Reference Material. This paper describes the preparation of an urban dust reference material (CRM 605), the homogeneity and stability studies, and the analytical work performed for the certification of the trimethyl‐lead content (7.9 ± 1.2 μg kg−1 by mass). Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
9.
Matthias Koch Almuth Liebich Tin Win Irene Nehls Arne Lund Kvernheim Oddvar Ringstad Frøydis Oreld 《Accreditation and quality assurance》2006,11(3):122-129
The 2-year international joint project HYCREF (Contract-No. G6RD-CT-2002-00854), funded by the European Commission in the 5th Framework programme, aimed to develop methods to prepare homogenous and stable water-, soil- and waste reference materials contaminated with mineral oil hydrocarbons and to test certify the mineral oil content by gas chromatographic methods. As mineral oil products are important sources for environmental contaminations, appropriate reference materials certified by using the new gas chromatographic methods (soil: ISO/FDIS 16703, waste: prEN 14039 and KW/04, water: ISO 9377-2) are highly needed. Additional to the HYCREF-results presented in part I–mineral contaminated soils–this second paper gives an overview of the feasibility study for the preparation and test certification of three waste reference materials (offshore marine sediment, building material and industrial waste). The following specifications, which had been defined in the project work plan, were reached successfully: uncertainty of the mineral oil content resulting from the certification exercise ≤5% and a between-bottle inhomogeneity of ≤3%. All three materials have been evaluated for long- and short term stability. They contain different levels and types of mineral oil and cover the full application range of ISO/FDIS 16703 and prEN 14039 (100–10,000 mg/kg). The expanded uncertainties U
cert of the three materials are about 6%. In this way, they are comparable to ERM®-CC015a (U
cert=7.1%, mineral oil in a river sediment) and are suited to close the present gap of commercially available CRM for mineral oil determination in waste. 相似文献
10.
Davis WC Christopher SJ Pugh RS Donard OF Krupp EA Point D Horvat M Gibicar D Kljakovic-Gaspic Z Porter BJ Schantz MM 《Analytical and bioanalytical chemistry》2007,387(7):2335-2341
This paper describes the development of two independent analytical methods for the extraction and quantification of methylmercury
from marine biota. The procedures involve microwave extraction, followed by derivatization and either headspace solid-phase
microextraction (SPME) with a polydimethylsiloxane (PDMS)-coated silica fiber or back-extraction into iso-octane. The identification
and quantification of the extracted compounds is carried out by capillary gas chromatography/mass spectrometric (GC/MS) and
inductively coupled plasma mass spectrometric (GC/ICP-MS) detection. Both methods were validated for the determination of
methylmercury (MeHg) concentrations in a variety of biological standard reference materials (SRMs) including fresh-frozen
tissue homogenates of SRM 1946 Lake Superior fish tissue and SRM 1974a organics in mussel tissue (Mytilus edulis) and then applied to the certification effort of SRM 1947 Lake Michigan fish tissue and SRM 1974b organics in mussel tissue
(Mytilus edulis). While past certifications of methylmercury in tissue SRMs have been based on two independent methods from the National
Institute of Standards and Technology (NIST) and participating laboratories, the methods described within provide improved
protocols and will allow future certification efforts to be based on at least two independent analytical methods within NIST. 相似文献
11.
This paper describes the history and scheme of reference materials and standard solutions for titrimetry in Japan. Titrimetry
is one of the most fundamental and precise methods for determination of a constituent, based on the effective purity of reference
materials in stoichiometric analysis. It has wide-ranging applications based on titrimetric reactions such as neutralization,
redox, chelatometric, and precipitation titration processes, which are used in various analytical fields all over the world.
Japanese Industrial Standards (JIS) have played an important role in establishing a stable supply of reference materials for
titrimetry since the 1950s. There are several reports of preparations and their determination, including coulometric studies,
in order to establish highly reliable reference materials. This paper briefly reviews the schemes and studies of standardization
through the provision of reference materials and standard solutions based on JIS, and several applications in other standards.
Presented at Berm-11, October 2007, Tsukuba, Japan. 相似文献
12.
Pressurized liquid extraction with an integrated carbon trap (PLE-C) has recently been developed for fast and efficient analysis
of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in food and feed. The method has also been tested, but not verified,
for use on more complex soil samples, such as soil, sediment and fly ash. Hence, the primary aim of this study was to verify
that PLE-C can produce reliable data for PCDDs/PCDFs in various abiotic matrixes. A second aim was to find a replacement for
the previously used AX21 active carbon that is currently not commercially available. The performance of the PLE-C was evaluated
using both single congener concentrations and toxic equivalency potentials (TEQ-pot) of three (soil, sediment and fly ash)
certified reference materials. The results clearly show that PLE-C can be used for abiotic samples and that a commercially
available carbon (Norit SA 4PAH HF) can replace the AX-21 carbon in the carbon trap. The TEQ-pot values obtained for the soil
and sediment samples were within the uncertainty limits of the corresponding certified values, as were the determinations
of single congener concentrations. PLE-C therefore has great potential for determination of PCDDs/PCDFs in soil and sediment
samples. The TEQ-pot result for the fly ash was slightly lower than the certified TEQ-pot value, but it is still within the
uncertainty limits of the certified value. Out of the single congener concentrations all but four (out of 17) agreed well
with the values. Hence, PLE-C may potentially be used also for fly ash—after slight modifications. The integrated PLE-C and
cleanup procedure is less labour-intensive than traditional methods such as Soxhlet extraction followed by a multistep cleanup,
and consumes smaller quantities of ultrapure solvents than the commonly used Power-Prep system. In addition, PLE-C is capable
of larger sample throughputs than the conventional methods. Thus, PLE-C is a promising alternative to the currently used sample
preparation procedures for dioxins in abiotic samples.
Figure PLE with integraded carbon trap for rapid PCDD/Fs analysis
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
13.
The NIST program for environmental Standard Reference Materials (SRM) includes materials covering a range of matrices, mass
fraction values and analytes. For many SRMs, mass fraction data are accumulated, incidentally, over time, as these are used
routinely for quality assurance purposes. Although these are not formal stability studies, data generated may be useful in
assessing stability. To evaluate the potential for assessing material stability from incidental use of SRMs, results of neutron
activation analysis performed from 1992 through 2008 were compiled for SRM 1547 Peach Leaves and SRM 1566a Oyster Tissue.
Results indicate that incidental use of SRMs yields useful information on SRM stability. 相似文献
14.
Slurry-ETA-AAS is used to determine lead in plant materials. The stability of the slurry was studied and it was shown that, when NH4H2PO4 modifier is added, the shape of the time resolved absorbance signal for the sample and the standards is similar and the calibration line obtained using aqueous standards is parallel to the standard addition line. Results obtained for several reference materials (lead contents between 6.1 and 64.4 g/g) were in good agreement with the certified value, the relative standard deviation being 3–9%. 相似文献
15.
Poster DL Schantz MM Kucklick JR Lopez de Alda MJ Porter BJ Pugh R Wise SA 《Analytical and bioanalytical chemistry》2004,378(5):1213-1231
Three new mussel tissue standard reference materials (SRMs) have been developed by the National Institute of Standards and Technology (NIST) for the determination of the concentrations of organic contaminants. The most recently prepared material, SRM 1974b, is a fresh frozen tissue homogenate prepared from mussels (Mytilus edulis) collected in Boston Harbor, Massachusetts. The other two materials, SRMs 2977 and 2978, are freeze-dried tissue homogenates prepared from mussels collected in Guanabara Bay, Brazil and Raritan Bay, New Jersey, respectively. All three new mussel tissue SRMs complement the current suite of marine natural-matrix SRMs available from NIST that are characterized for a wide range of contaminants (organic and inorganic). SRM 1974b has been developed to replace its predecessor SRM 1974a, Organics in Mussel Tissue, for which the supply is depleted. Similarly, SRMs 2977 and 2978 were developed to replace a previously available (supply depleted) freeze-dried version of SRM 1974a, SRM 2974, Organics in Freeze-Dried Mussel Tissue. SRM 1974b is the third in a series of fresh frozen mussel tissue homogenate SRMs prepared from mussels collected in Boston Harbor starting in 1988. SRM 1974b has certified concentration values for 22 polycyclic aromatic hydrocarbons (PAHs), 31 polychlorinated biphenyl congeners (PCBs), and 7 chlorinated pesticides. Reference values are provided for additional constituents: 16 PAHs, 8 PCBs plus total PCBs, 6 pesticides, total extractable organics, methylmercury, and 11 trace elements. PAH concentrations range from about 2 ng g–1 dry mass (cyclopenta[cd]pyrene) to 180 ng g–1 dry mass (pyrene). PCB concentrations range from about 2 ng g–1 dry mass (PCB 157) to 120 ng g–1 dry mass (PCB 153). The reference value for total PCBs in SRM 1974b is (2020 ± 420) ng g–1 dry mass. Pesticide concentrations range from about 4 ng g–1 dry mass (4,4-DDT) to 40 ng g–1 dry mass (4,4-DDE). SRM 2977 has certified values for 14 PAHs, 25 PCB congeners, 7 pesticides, 6 trace elements, and methylmercury. Reference values for 16 additional PAHs and 9 inorganic constituents are provided, and information values are given for 23 additional trace elements. SRM 2978 has certified and reference concentrations for 41 and 22 organic compounds, respectively, and contains contaminant levels similar to those of SRM 1974b. Organic contaminant levels in SRM 2977 (mussels from Guanabara Bay, Brazil) are typically a factor of 2 to 4 lower than those in SRM 1974b and SRM 2978. The organic contaminant concentrations in each new mussel tissue SRM are presented and compared in this paper. In addition, a chronological review of contaminant concentrations associated with mussels collected in Boston Harbor is discussed as well as a stability assessment of SRM 1974a.Electronic Supplementary Material Supplementary material is available in the online version of this article at . A link in the frame on the left on that page takes you directly to the supplementary material. 相似文献
16.
Schantz MM Bedner M Long SE Molloy JL Murphy KE Porter BJ Putzbach K Rimmer CA Sander LC Sharpless KE Thomas JB Wise SA Wood LJ Yen JH Yarita T NguyenPho A Sorenson WR Betz JM 《Analytical and bioanalytical chemistry》2008,392(3):427-438
As part of a collaboration with the National Institutes of Health’s Office of Dietary Supplements and the Food and Drug Administration’s
Center for Drug Evaluation and Research, the National Institute of Standards and Technology has developed two standard reference
materials (SRMs) representing different forms of saw palmetto (Serenoa repens), SRM 3250 Serenoa repens fruit and SRM 3251 Serenoa repens extract. Both of these SRMs have been characterized for their fatty acid and phytosterol content. The fatty acid concentration
values are based on results from gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS)
analysis while the sterol concentration values are based on results from GC-FID and liquid chromatography with mass spectrometry
analysis. In addition, SRM 3250 has been characterized for lead content, and SRM 3251 has been characterized for the content
of β-carotene and tocopherols. SRM 3250 (fruit) has certified concentration values for three phytosterols, 14 fatty acids
as triglycerides, and lead along with reference concentration values for four fatty acids as triglycerides and 16 free fatty
acids. SRM 3251 (extract) has certified concentration values for three phytosterols, 17 fatty acids as triglycerides, β-carotene,
and γ-tocopherol along with reference concentration values for three fatty acids as triglycerides, 17 fatty acids as free
fatty acids, β-carotene isomers, and δ-tocopherol and information values for two phytosterols. These SRMs will complement
other reference materials currently available with concentrations for similar analytes and are part of a series of SRMs being
developed for dietary supplements.
Contribution of the US Government; not subject to copyright 相似文献
17.
Fit-for-purpose shellfish reference materials for internal and external quality control in the analysis of phycotoxins 总被引:1,自引:0,他引:1
The need for reference materials for quality control of analysis of foodstuffs has been stressed frequently. This has been
particularly true in the phycotoxins field, where there is a great shortage of both pure calibration standards and reference
materials. Worldwide there are very few independent bodies that produce certified reference materials for phycotoxins, the
main producers currently being the National Research Council Canada and the Japanese Food Research Laboratory. Limited availability
of contaminated shellfish and algae, as well as the time and knowledge necessary for the production of adequate reference
materials, continuously lead to limited editions of certified reference materials and even more limited production of in-house
reference materials. The restricted availability of in-house quality control materials promotes the rapid use of the limited
certified reference materials, which in turn hampers the production of the suite of materials required globally for complete
protection of public health. This paper outlines the various options that analysts can pursue in the use of reference materials
for internal and external quality control, with a view to optimising the efforts of both reference materials users and reference
materials producers. For this purpose, the logical sequence is reviewed from the discovery of a new bioactive compound in
shellfish, through initial method development up to regulation for food safety purposes including accepted reference methods.
Subsequently, the requirements for and efforts typically spent in the production and characterisation of laboratory reference
materials, certified reference materials and other test materials used in inter-laboratory studies or proficiency testing,
in the area of marine biotoxins are evaluated. Particular emphasis is put on practical advice for the preparation of in-house
reference materials. The intricate link between reference material characterisation and method performance is outlined to
give guidance on the appropriate in-house method validation in the rapidly developing field of phycotoxins.
相似文献
18.
Nobuyasu Hanari Nobuyasu Itoh Ryoko Iwasawa Yoshie Aoyagi Masahiko Numata 《International journal of environmental analytical chemistry》2018,98(1):56-66
A certified reference material (CRM) for the determination of perfluorooctane sulfonate (PFOS) in acrylonitrile-butadiene-styrene (ABS) resin (NMIJ CRM 8155-a) has been issued by the National Metrology Institute of Japan (NMIJ). The bulk material was prepared by mixing commercial ABS resin powder and potassium PFOS and cut into square plates (20 × 20 mm, 2 mm thick) as the CRM. Analytical processes combined with isotope-dilution mass spectrometry and liquid chromatography/mass spectrometry were optimised and applied for characterisation. One of the approaches adopted by NMIJ for certification is that results from two or more primary methods of measurement should be used; thus, two optimised isotope-dilution mass spectrometric methods (Methods 1 and 2 with reprecipitation and with reprecipitation/solid phase extraction, respectively, were validated mutually and employed) were used to determine the certified value. Homogeneity and stability of the square plates were evaluated and their uncertainty contributions (as relative standard uncertainties) were 1.43% for inhomogeneity and 6.96% for approximately two years’ instability. The certified mass fraction of linear PFOS (heptadecafluoro-1-octanesulfonic acid) in the CRM with expanded uncertainty (coverage factor k = 2, approximately 95% confidence interval) was (33.1 ± 5.0) mg kg?1 as free acid of PFOS. 相似文献
19.
Kristien Vercoutere Rita Cornelis Steen Dyg Louis Mees Jytte Molin Christensen Kirsten Byrialsen Benny Aaen Philippe Quevauviller 《Mikrochimica acta》1996,123(1-4):109-117
The production of reference materials for quality control of Cr(III) and Cr(VI) speciation in environmental samples is described. It concerns in the first place two lyophilized solutions containing Cr(III) and Cr(VI) at different concentrations, respectively representative for drinking water and filter leaching solutions, and in the second place filters loaded with welding dust. Twenty-four laboratories with experience in the field participated in an intercomparison exercise organized to validate the suitability of the reference materials and to gauge the state-of-the-art of Cr speciation throughout Europe. The outcome of this exercise is discussed. 相似文献
20.
D. R. Baer 《Surface and interface analysis : SIA》2007,39(4):283-293
This paper summarizes the results of two surveys examining current needs for improved analyses of surfaces. Surfaces and interfaces are increasingly important to science and technologies associated with nanoparticles, nano‐structured materials and other complex materials including those associated with information systems and medical or biological applications. Adequate characterization of advanced materials frequently requires application of more than one analysis method along with the need to analyze data in increasingly sophisticated and sometimes interrelated ways. It is useful for both new and experienced analysts to have ready access to best practices for obtaining accurate and useful information from a variety of different analysis tools. The International Organization for Standardization (ISO) Committee TC 201 on surface chemical analysis and the ASTM Committee E‐42 on surface analysis are working to address these needs by assembling guides and standards reflecting the collective experience and wisdom of experts in this community. Published in 2007 by John Wiley & Sons, Ltd 相似文献