TY - JOUR A1 - Becker, Roland A1 - Buge, Hans-Gerhard A1 - Nehls, Irene T1 - The determination of adsorbable organically bound halogens (AOX) in soil: interlaboratory comparisons and reference materials JF - Accreditation and quality assurance N2 - The interlaboratory variability in the quantification of adsorbable organically bound halogens (AOX) in industrially contaminated soil is presented. Three consecutive rounds of a proficiency testing scheme, in which between 88 and 119 routine laboratories participated, yielded relative reproducibility standard deviations between 7 and 20% at AOX contents between 10.9 and 268 mg kg-1. Nineteen laboratories with established proficiency were invited to participate in the certification of the AOX content in three soil reference materials meant for the internal quality control in analytical laboratories. The certified values are (1349 ± 59) mg kg-1, (80 ± 7) mg kg-1 and (102 ± 8) mg kg-1, respectively. KW - Certified reference materials KW - European Reference Material KW - Proficiency testing KW - Organohalogen compounds KW - Summation parameter PY - 2007 DO - https://doi.org/10.1007/s00769-007-0308-z SN - 0949-1775 SN - 1432-0517 VL - 12 IS - 12 SP - 647 EP - 651 PB - Springer CY - Berlin AN - OPUS4-16670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bremser, Wolfram A1 - Becker, Roland A1 - Kipphardt, Heinrich A1 - Lehnik-Habrink, Petra A1 - Panne, Ulrich A1 - Töpfer, Antje T1 - Stability testing in an integrated scheme JF - Accreditation and quality assurance N2 - ISO Guide 35 deals with RM stability issues and scrutinizes the evaluation of stability testing results under the assumption that either there is no trend at all (a rather rare situation), or any observed deterministic change is insignificant and thus can be neglected. However, market demands for reliable reference materials are obviously not limited to stable or at least seemingly stable materials. In many analytical applications, analytes and measurands under consideration are known, or at least suspected, to be unstable on time scales that may vary widely from measurand to measurand. The Federal Institute for Materials Research and Testing (BAM) has developed (and successfully uses) an integrated approach in its certification practice. The approach is based on an initial stability study and subsequent post-certification monitoring. Data evaluation is model-based and takes advantage of all information collected in the stability testing scheme(s). It thus allows one to deal with any kind of instability observed, to assess limiting time intervals at any stress condition in the range tested, to estimate a final expiry date for materials with detected instabilities or the maximum admissible re-testing interval for seemingly stable materials, and to assess maximum admissible stress loads during delivery of the material to the customer. The article describes (and exemplifies) typical study layout, the model selection, and the integrated data assessment. KW - Certified reference materials KW - Stability KW - Shelf life KW - Arrhenius model KW - ERM PY - 2006 DO - https://doi.org/10.1007/s00769-006-0152-6 SN - 0949-1775 SN - 1432-0517 VL - 11 IS - 10 SP - 489 EP - 495 PB - Springer CY - Berlin AN - OPUS4-14063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hesse, Almut A1 - Weller, Michael G. T1 - Protein Quantification by Derivatization-Free High-Performance Liquid Chromatography of Aromatic Amino Acids JF - Journal of Amino Acids N2 - Amino acid analysis is considered to be the gold standard for quantitative peptide and protein analysis. Here, we would like to propose a simple HPLC/UV method based on a reversed-phase separation of the aromatic amino acids tyrosine (Tyr), phenylalanine (Phe), and optionally tryptophan (Trp) without any derivatization. The hydrolysis of the proteins and peptides was performed by an accelerated microwave technique, which needs only 30 minutes. Two internal standard compounds, homotyrosine (HTyr) and 4-fluorophenylalanine (FPhe) were used for calibration. The limit of detection (LOD) was estimated to be 0.05 µM (~10 µg/L) for tyrosine and phenylalanine at 215 nm. The LOD for a protein determination was calculated to be below 16 mg/L (~300 ng BSA absolute). Aromatic amino acid analysis (AAAA) offers excellent accuracy and a precision of about 5% relative standard deviation, including the hydrolysis step. The method was validated with certified reference materials (CRM) of amino acids and of a pure protein (bovine serum albumin, BSA). AAAA can be used for the quantification of aromatic amino acids, isolated peptides or proteins, complex peptide or protein samples, such as serum or milk powder, and peptides or proteins immobilized on solid supports. KW - Protein analysis KW - Proteomics KW - Peptides KW - Metrology KW - Certified reference materials KW - Amino acid analysis KW - Hydrolysis KW - Microwave KW - Tyrosine KW - Phenylalanine KW - Tryptophan PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370215 DO - https://doi.org/10.1155/2016/7374316 SN - 2090-0112 SN - 2090-0104 VL - 2016 SP - Article 7374316, 1 EP - 8 PB - Hindawi CY - Cairo, London, New York AN - OPUS4-37021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klobes, Peter A1 - Röhl-Kuhn, Barbara A1 - Meyer, Klaus T1 - Zertifizierung von Referenzmaterialien am Beispiel poröser hochdisperser Feststoffe für die Methode der Gasadsorption JF - GIT : Labor-Fachzeitschrift N2 - Entsprechend den BCR Guidelines für die Herstellung von zertifizierten Referenzmaterialien (CRMs) und den ISO Guides 30-35 wurden CRMs mit den Kenngrößen spezifische Oberfläche, spezifisches Porenvolumen und Porenradius hergestellt. Als Methode wurde die Gasadsorption verwendet. Die Zertifizierungsanalyse und die Referenzmaterialien selbst werden beschrieben. KW - Zertifizierte Referenzmaterialien KW - Gasadsorption KW - Spezifische Oberfläche KW - Spezifisches Porenvolumen KW - Porenradius KW - Poröse Materialien KW - Disperse Feststoffe KW - Certified reference materials KW - Gas adsorption KW - Specific surface area KW - Specific pore volume KW - Pore radius KW - Porous materials KW - Dispersed solids PY - 1998 SN - 0016-3538 VL - 42 SP - 214 EP - 217 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-11982 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Bremser, Wolfram A1 - Köppen, Robert A1 - Siegel, David A1 - Töpfer, Antje A1 - Nehls, Irene T1 - Development of two certified reference materials for acrylamide determination in foods JF - Journal of agricultural and food chemistry N2 - Certified reference materials (CRMs) are a versatile tool for quality assurance in the chemical laboratory. In the case of acrylamide analysis, the availability of appropriate materials was rather limited. This lack of acrylamide matrix CRMs has now been overcome by the development of two European reference materials (ERM) for the determination of acrylamide in food (crispbread, ERM-BD272, and rusk, ERM-BD274). This article describes the preparation of the materials, provides the results of the homogeneity and stability studies, and presents and discusses the outcome of the certification studies. Expert laboratories from different European countries took part in the certification studies using various analytical methods. The acrylamide mass fractions were certified to 980 µg kg-1 for crispbread and 74 µg kg-1 for rusk. KW - Certified reference materials KW - ERM KW - Acrylamide KW - Crispbread KW - Rusk KW - Quality assurance KW - Homogeneity KW - Stability PY - 2009 DO - https://doi.org/10.1021/jf901329t SN - 0021-8561 SN - 1520-5118 VL - 57 IS - 18 SP - 8202 EP - 8207 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-19888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steiger, Thomas A1 - Pradel, Rita T1 - COMAR - status and user possibilities JF - CITAC News : Cooperation in international traceability in analytical chemistry KW - COMAR database KW - Certified reference materials KW - CRM KW - Reference materials KW - RM KW - CITAC PY - 2005 SP - 9 EP - 11 CY - Jerusalem, Israel AN - OPUS4-7064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steiger, Thomas A1 - Pradel, Rita T1 - Update on COMAR - the Internet Database for Certified Reference Materials JF - MAPAN - Journal of metrology society of India KW - COMAR database KW - Certified reference materials KW - CRM PY - 2004 SN - 0970-3950 VL - 19 IS - 4 SP - 203 EP - 207 PB - Metrology Society of India CY - New Delhi AN - OPUS4-5986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steiger, Thomas A1 - Pradel, Rita T1 - Update on COMAR: the Internet database for certified reference materials JF - Accreditation and quality assurance N2 - This paper describes the COMAR database for certified reference materials (CRMs). The Web-based version of COMAR is freely accessible via the Internet. COMAR was established to assist laboratories in finding the CRMs needed. The database is maintained in a collaboration of the world’s major CRM producers. The planned changes in the database as agreed at the last COMAR council meeting in Prague in May 2006 are indicated. KW - COMAR KW - Database KW - Reference materials KW - Certified reference materials PY - 2007 SN - 0949-1775 SN - 1432-0517 VL - 12 IS - 5 SP - 265 EP - 268 PB - Springer CY - Berlin AN - OPUS4-14821 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steiger, Thomas A1 - Pradel, Rita T1 - Improvement of COMAR database JF - CITAC News : Cooperation in international traceability in analytical chemistry N2 - COMAR, the international database for certified reference materials (CRM) has been improved by BAM for the benefit of CRM users and producers worldwide. The usefulness of reference materials (RM) is beyond question. RM provide "measurement benchmarks" for materials testing and chemical analysis and ensure reliability and worldwide comparability of measurements in these fields. The use of RM is a basic requirement for quality assurance. In addition CRM are very important for establishing traceability, especially in chemical analysis. Even in the age of web based technologies and services finding a proper reference material is a demanding task especially for newcomers or for new kind of materials. The best choice ist to use reference material databases that collect data from several RM producers and provide information in a uniform way. COMAR has been established to help laboratories to find the proper CRM needed. The database gives information on the worldwide availibility of certified reference materials. BAM has recently improved COMAR in order to make searching in COMAR more simple and target-orientated and to make the process of updating data more efficient. KW - COMAR KW - Reference materials KW - Certified reference materials KW - RM KW - CRM KW - Metrology in chemistry PY - 2009 IS - February SP - 19 EP - 21 CY - Jerusalem, Israel AN - OPUS4-19074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steiger, Thomas A1 - Pradel, Rita A1 - Bremser, Wolfram A1 - Anchutina, E. A. T1 - COMAR - The international database for certified reference materials JF - Certified reference materials KW - COMAR KW - CRM KW - RM KW - Database KW - Certified reference materials PY - 2014 SN - 2077-1177 IS - 1 SP - 71 EP - 80 AN - OPUS4-30943 LA - rus AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -