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  Subjects -> CHEMISTRY (Total: 891 journals)
    - ANALYTICAL CHEMISTRY (55 journals)
    - CHEMISTRY (621 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (51 journals)
    - PHYSICAL CHEMISTRY (70 journals)

CHEMISTRY (621 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 14)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 43)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 21)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 26)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 41)
ACS Nano     Full-text available via subscription   (Followers: 273)
ACS Photonics     Full-text available via subscription   (Followers: 14)
ACS Symposium Series     Full-text available via subscription  
ACS Synthetic Biology     Full-text available via subscription   (Followers: 24)
Acta Chemica Iasi     Open Access   (Followers: 5)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 6)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 6)
Advanced Functional Materials     Hybrid Journal   (Followers: 57)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 66)
Advances in Chemical Science     Open Access   (Followers: 18)
Advances in Chemistry     Open Access   (Followers: 21)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 19)
Advances in Drug Research     Full-text available via subscription   (Followers: 23)
Advances in Environmental Chemistry     Open Access   (Followers: 5)
Advances in Enzyme Research     Open Access   (Followers: 10)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 25)
Advances in Nanoparticles     Open Access   (Followers: 15)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 16)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 3)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 64)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 17)
American Journal of Chemistry     Open Access   (Followers: 30)
American Journal of Plant Physiology     Open Access   (Followers: 11)
American Mineralogist     Hybrid Journal   (Followers: 15)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 165)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 243)
Annales UMCS, Chemia     Open Access  
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 31)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 4)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 348)
Biochemistry Insights     Open Access   (Followers: 6)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Full-text available via subscription   (Followers: 21)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 130)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 84)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 2)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 71)
Catalysis for Sustainable Energy     Open Access   (Followers: 8)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 10)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 18)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 73)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 26)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 22)
Chemical Reviews     Full-text available via subscription   (Followers: 191)
Chemical Science     Open Access   (Followers: 24)
Chemical Technology     Open Access   (Followers: 24)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 24)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Hybrid Journal   (Followers: 7)
Chemistry - A European Journal     Hybrid Journal   (Followers: 161)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 16)
Chemistry and Materials Research     Open Access   (Followers: 21)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 252)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 19)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 4)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 11)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 11)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography     Open Access   (Followers: 2)
Chromatography Research International     Open Access   (Followers: 6)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 1)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 6)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 22)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access  
Composite Interfaces     Hybrid Journal   (Followers: 7)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 11)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 3)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 6)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal  
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 14)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 69)
Current Trends in Biotechnology and Chemical Research     Open Access   (Followers: 3)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  

        1 2 3 4 | Last

Journal Cover Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement
  Journal Prestige (SJR): 0.378
  Citation Impact (citeScore): 30
  Number of Followers: 26  
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0949-1775 - ISSN (Online) 1432-0517
   Published by Springer-Verlag Homepage  [2350 journals]
  • Measurements recovery evaluation from the analysis of independent
           reference materials: analysis of different samples with native quantity
           spiked at different levels
    • Authors: Rui M. S. Cordeiro; Constantino M. G. Rosa; Ricardo J. N. Bettencourt da Silva
      Pages: 57 - 71
      Abstract: Measurement uncertainty evaluation involves combining uncertainty components reflecting all relevant random and systematic effects: the precision and trueness uncertainty components, respectively. Typically, trueness is assessed through the analysis of various materials with known reference value, such as certified reference materials (CRMs) or spiked samples, from which it should be decided about the relevance and the need to correct measurement results for systematic effects. Algorithms proposed so far to assess systematic effects are only applicable to the analysis of the same reference material type or assume that some uncertainty components affecting evaluations are negligible or constant. This work presents detailed algorithms for the assessment of systematic effects, through the determination of recovery and the respective recovery uncertainty, applicable to the analysis of various independent reference materials, such as CRMs and spiked samples with native analyte. These algorithms are applicable to cases where native analyte and/or spiking values are associated with relevant and significantly different uncertainties allowing for a reliable assessment of systematic effects and measurement uncertainty for these complex cases. This methodology was successfully applied to the quantification of Na, K, Mg, Ca, Cr, Mn, Fe and Cu in water samples from two proficiency testing schemes, by ICP-OES, where recovery was estimated from the analysis of samples with different native concentrations and spiked at different levels. The relative expanded uncertainties of the measurement results ranged from 28.9 % to 3.9 % and are fit for the monitoring of environmental water samples in accordance with criteria set in the European Union legislation.
      PubDate: 2018-04-01
      DOI: 10.1007/s00769-017-1296-2
      Issue No: Vol. 23, No. 2 (2018)
       
  • Measurement uncertainty: requirements set in the accreditation standards
    • Authors: Kyriacos C. Tsimillis
      Pages: 109 - 114
      Abstract: Measurement uncertainty is of high importance to all testing and calibration laboratories and those involved in sampling activities. Its evaluation requires good understanding of the method implemented and realisation of all factors contributing to it. It is required that the users of the results fully understand the meaning of uncertainty stated on test reports and calibration certificates and, when needed, ask for clarifications. Laboratories, both the accredited ones and those being prepared towards their accreditation, need to take this into account when evaluating the uncertainty of their results. Competent authorities need to consider the stated uncertainty to compare the result with a legislative limit. The producer can decide on adjustments needed. The consumer may find it more difficult to understand how this “uncertain component” of the results could affect their health, safety or economic rights. This article describes the relevant requirements of the accreditation standards referring both to testing and calibration laboratories and to proficiency testing and reference material producers. Further to this, the article explains why all these factors have to be considered by a laboratory.
      PubDate: 2018-04-01
      DOI: 10.1007/s00769-018-1310-3
      Issue No: Vol. 23, No. 2 (2018)
       
  • Occurrence of nitrate in vegetables and dietary exposure assessment for
           the Cypriot adolescent consumers
    • Authors: Georgios Stavroulakis; Demetris Kafouris; Maria Christofidou; Lefkios Paikousis; Eftychia Christou; Maro Christodoulidou; Popi Kanari; Eleni Ioannou-Kakouri
      Pages: 115 - 122
      Abstract: In this study, a simple, rapid and sensitive ion chromatography method was used for the determination of mass fraction nitrate (mg kg−1) in 396 samples of vegetables. The method performance characteristics were determined after spiking blank samples. The mean recoveries in vegetables ranged from 94.0 % to 108.7 %. Limits of detection and quantification were 10 mg kg−1 and 30 mg kg−1, respectively. The results showed the mass fraction nitrate in vegetables was in the range of 10 mg kg−1–5619 mg kg−1. Leafy, root and stem vegetables, and herbs were the most contaminated, compared to other vegetables. Approximately 87 % of the samples were contaminated with nitrate; however, none of the samples analyzed was above the maximum limits for nitrate in vegetables. The dietary nitrate intake through consumption of vegetables was estimated for the adolescent population in Cyprus. The mean and 95th percentile intake values, based on median nitrate concentrations, were 1.12 kg d−1 and 3.42 mg kg−1 d−1, respectively. A small percentage (3.3 %) of the adolescent population had a nitrate intake above the Acceptable Daily Intake (3.7 mg kg−1 d−1). Lettuce and other leafy vegetables (spinach, rucola, purslane, beet leaves) contributed nearly 60 % to the overall nitrate exposure (mg kg−1 d−1).
      PubDate: 2018-04-01
      DOI: 10.1007/s00769-018-1311-2
      Issue No: Vol. 23, No. 2 (2018)
       
  • Congresses, conferences, workshops and courses
    • Pages: 123 - 123
      PubDate: 2018-04-01
      DOI: 10.1007/s00769-018-1314-z
      Issue No: Vol. 23, No. 2 (2018)
       
  • Accurate determination of formaldehyde amount fraction in cylinders using
           mixtures of primary standards of formaldehyde in nitrogen prepared by a
           gravimetric permeation method
    • Abstract: A reliable method for the quantification of formaldehyde (HCHO) amount fractions is required, because the results of comparisons between individual techniques used for the quantification of HCHO amount fractions often disagree owing to unknown causes. One reliable method comprises the quantification of HCHO using working gas standards in which the HCHO amount fraction is linked to the International System of Units (SI). In this work, the SI traceability of HCHO amount fractions in mixtures of commercial HCHO in nitrogen in cylinders used as working gas standards was established by calibrating them against primary gas standard mixtures (mixtures of HCHO in N2), which were prepared by a permeation method and were traceable to SI. The expanded relative uncertainties (k = 2) of the amount fractions in the primary gas standard mixtures were less than 0.6 %. The quantitative values of the amount fractions in the working gas standards had relative expanded uncertainties (k = 2) of 0.7 %–0.9 %.
      PubDate: 2018-06-06
      DOI: 10.1007/s00769-018-1321-0
       
  • Validation guidelines for PCR workflows in bioterrorism preparedness, food
           safety and forensics
    • Authors: Johannes Hedman; Moa Lavander; Emelie Näslund Salomonsson; Tomas Jinnerot; Lina Boiso; Bertil Magnusson; Peter Rådström
      Abstract: The polymerase chain reaction (PCR) is the backbone of contemporary DNA/RNA analysis, ideally enabling detection of one or just a few target molecules. However, when analysing food or forensic samples the analytical procedure is often challenged by low amounts of poor quality template molecules and complex matrices. Applying optimised and validated methods in all steps of the analysis workflow, i.e. sampling, sample treatment, DNA/RNA extraction and PCR (including reverse transcription for RNA analysis), is thus necessary to ensure the reliability of analysis. In this paper, we describe how in-house validation can be performed for the different modules of the diagnostic PCR process, providing practical examples as tools for laboratories in their planning of validation studies. The focus is analysis of heterogeneous samples with interfering matrices, with relevance in food testing, forensic DNA analysis, bioterrorism preparedness and veterinary medicine. Our objective is to enable rational in-house validation for reliable and swift quality assurance when results are urgent, for example in the event of a crisis such as a foodborne outbreak or a crime requiring the analysis of a large number of diverse samples. To that end, we explain the performance characteristics associated with method validation from a PCR and biological sample matrix perspective and suggest which characteristics to investigate depending on the type of method to be validated. Also, we include a modular approach to validation within the PCR workflow, aiming at efficient validation and a flexible use of methods.
      PubDate: 2018-06-05
      DOI: 10.1007/s00769-018-1319-7
       
  • Congresses, conferences, workshops and courses
    • PubDate: 2018-06-04
      DOI: 10.1007/s00769-018-1324-x
       
  • Correction to: Measurement uncertainty: requirements set in the
           accreditation standards
    • Abstract: Unfortunately, the references 12 and 13 were incorrectly published in the original publication. The correct references are:
      PubDate: 2018-05-30
      DOI: 10.1007/s00769-018-1323-y
       
  • Motivations, benefits and challenges on ISO/IEC 17025 accreditation of
           higher education institution laboratories
    • Abstract: Accreditation of laboratories from higher education institutions (HEI) according to ISO/IEC 17025 contributes to meeting national regulatory requirements and to the involvement of countries in foreign trade. Additionally, these laboratories can benefit from the introduction of quality concepts and practices. Worldwide, testing and calibration laboratories from HEI face several challenges toward accreditation. This paper presents and comments on the characteristics, motivations, benefits and challenges toward accreditation of HEI laboratories. Responses to questionnaires sent to accredited HEI laboratories in the American continent showed that the vast majority undertakes tests for external clients, uses standardized methods and performs tests other than those accredited. Institutional decisions, external clients and regulatory requirements were the main motivators for accreditation. Lack of financial resources and lack of personnel were considered the main difficulties, while a preexisting laboratory structure and a motivated staff, the main facilitators toward accreditation. The resulting data allow a better understanding of the characteristics and difficulties of these laboratories. Additionally, this paper aims the identification of strategies to overcome problems faced by laboratories in HEI and research institutes, in order to promote the increase of their accreditation globally.
      PubDate: 2018-05-25
      DOI: 10.1007/s00769-018-1317-9
       
  • Changes to proficiency testing in developing countries over the last
           10 years
    • Abstract: Participation in proficiency testing schemes is necessary and beneficial for all testing laboratories across the world. Laboratories in developing countries face particular challenges in this context. These have been discussed during the last 10 years at various international workshops organized by Eurachem. An online survey on the developments during this period has been performed, and the results are presented here. Affordability and availability of proficiency tests as well as transport and customs issues are still the major problems. Installation of national or regional schemes could solve some of these problems, but their sustainability is a challenge. Finally, the author’s personal opinion on the conclusions that can be drawn from the results of the survey is given.
      PubDate: 2018-05-23
      DOI: 10.1007/s00769-018-1322-z
       
  • Improved continuous packaging method of the certified reference material
           for low water content in liquid
    • Authors: Ting Wang; Haifeng Wang; Heng Su; Xingliang Huang; Xiaoping Song; Kang Ma
      Abstract: Certified reference materials (CRMs) for water content are used to calibrate or validate Karl Fischer titrations for accuracy and consistency. Ampoules of CRMs with low water content are typically prepared by a continuous packaging method, and the water content may decrease or increase over time as the CRM is dispensed. In the present study, we measured the water activities of solutions of water in xylene with various water contents. We found the equilibrated humidity of the solution increased as the water content increased. An improved continuous packaging method using a pre-equilibrated bottle was employed to prepare the CRM of xylene for water content. The average water contents of the solutions dispensed into the ampoules are 73 mg/kg (relative standard deviation 1.6 %) and 221 mg/kg (relative standard deviation 0.4 %). There was no obvious shift in the water contents in ampoules of these CRMs over time. Analysis of variance indicated that the water contents of these two CRM candidates in ampoules were homogeneous, and the relative uncertainties in the water contents because of the inhomogeneity were 1.2 and 0.3 % for the low and high water contents, respectively. This simple method dispenses xylene under its equilibrated humidity condition, which reduces the exchange of water between the solution and headspace. This method will be useful for the preparation of CRMs for low water content.
      PubDate: 2018-04-25
      DOI: 10.1007/s00769-018-1318-8
       
  • Interferences, a neglected error source for clinical assays
    • Authors: Jan S. Krouwer
      Abstract: In clinical assays, interfering substances can cause large errors, which in turn can result in severe patient harm. Yet, perhaps because such errors are rare, not much attention is devoted to interferences. This is evident in specifications, which often focus on most, but not all of the results. Methods such as total error analysis, six sigma, and measurement uncertainty intervals are all useful but fail to properly account for interferences, and the Clinical Laboratory Standards Institute standard on interferences has misleading reporting advice. Suggestions are given to improve specifications, protocols, analyses, and reporting methods.
      PubDate: 2018-04-20
      DOI: 10.1007/s00769-018-1315-y
       
  • Report on the 40th meeting of ISO/REMCO
    • Authors: Angelique Botha; John Hammond; Hendrik Emons; Stéphane Sauvage
      Abstract: The 40th meeting of the Reference Material Committee of ISO, ISO/REMCO, was held in Berlin, Germany, from 26 to 29 June 2017, and was hosted by the Federal Institute for Materials Research and Testing (BAM) and the German Institute for Standardization (DIN). This report details and summarizes the discussions and findings of the associated group sessions, and meetings.
      PubDate: 2018-04-03
      DOI: 10.1007/s00769-018-1313-0
       
  • Definition of reference values in synthetic emission monitoring bench
           loops
    • Authors: D. Cipriano; L. Fialdini
      Abstract: Proficiency tests (PTs) are widely used in order to certify capabilities of laboratories, determine and validate uncertainties and validate methods. One of the major difficulties in emission monitoring PTs is due to realisation of a stable and ‘metrological correct’ gas matrix, and, since now, the most common approach is based on emissions gases taken from industrial boilers, from which, therefore, the composition is ‘metrological’ unknown, or on ambient air added with compounds of interest, but, in this case, the chemical behaviour of the matrix may be different from real cases. Synthetic emissions loops give the possibility to fill this gap, but require particular protocols for definition of reference values and their uncertainties. One solution, adopted on the facility realised at RSE research centre in Italy, is shown.
      PubDate: 2018-03-27
      DOI: 10.1007/s00769-018-1312-1
       
  • Discussion on homogeneity assessment of reference materials based on
           uncertainty comparison method
    • Authors: Chonghua Liu; Zhiyong Ding; Yong Tian; Lezhou Yi; Ningshan Huang
      Abstract: An uncertainty comparison method is proposed to assess the homogeneity of reference materials. The method compares “standard uncertainty associated with between-unit variability” (ubb) with “target standard uncertainty” (utrg) or “measurement uncertainty” (umeas) to solve the problems in assessing homogeneity of reference materials. Methods for the calculation of ubb, utrg and umeas as well as criterion for the quantitative judgment of sample homogeneity are introduced. When ubb ≤ 0.3utrg, it shows the sample is considered to be homogeneous; when 0.3utrg < ubb ≤ 0.7utrg, the sample is considered to be sufficiently homogeneous for the intended use; and when ubb > 0.7utrg, the sample is considered to be inhomogeneous. The uncertainty comparison method is compared with the F test method and shown to be more objective for the assessment of the homogeneity of certified reference materials for the chemical testing of toys.
      PubDate: 2018-02-02
      DOI: 10.1007/s00769-017-1308-2
       
  • Congresses, conferences, workshops and courses
    • PubDate: 2018-02-01
      DOI: 10.1007/s00769-018-1309-9
       
  • Trueness verification survey for blood lead concentration measurement in
           Chinese clinical laboratories
    • Authors: Shuai Yuan; Wei Wang; Jianping Li; Mingxia Liu; Junwei Xin; Fa L. He; Kun Zhong; Zhi G. Wang
      Abstract: The results of trueness verification for blood lead measurement were analyzed in a 2016 nationwide external quality assessment (EQA) survey, in order to evaluate current approaches of blood lead measurement in Chinese Laboratories and their traceability to certified reference materials (CRMs). A panel of 2 frozen whole blood CRMs with values assigned by an absolute quantitative method was provided to 12 laboratories with satisfactory performances from the 2015 blood lead EQA scheme. Participants were required to measure the samples 5 times each day for 3 consecutive days and report all 15 data, which were then calculated for means and standard deviations. Data were statistically analyzed by adopted method groups, before comparing with the assigned values to assess the trueness of blood lead measurement using different approaches. Eleven laboratories reported on schedule, rendering a reporting rate of 91.7 %. The target values for the two batches were (37.6 ± 2.7) μg/L and (124.6 ± 4.5) μg/L, respectively. By the evaluation criterion of target value ± 20 µg/L, the pass rates were 72.7 % for the lower concentration and 54.5 % for the higher concentration, while 5 out of 11 laboratories delivered satisfactory results for both CRMs. The overall performance of the few participating laboratories in this EQA survey was basically acceptable by CLSI standard on the whole, yet barely desirable for the higher concentration. Therefore, trueness verification of blood lead measurement with CRMs is potentially necessary for national EQA schemes, which can be imperative as part of the validation procedures of analytical methods in clinical settings.
      PubDate: 2017-12-20
      DOI: 10.1007/s00769-017-1304-6
       
  • Correction to: Combined uncertainty factor for sampling and analysis
    • Authors: Michael H. Ramsey; Stephen L. R. Ellison
      Abstract: In the penultimate paragraph of the original publication, a confidence interval of 93 mg/kg to 971 mg/kg was reported. These values should be 114.5 mg/kg to 786.2 mg/kg.
      PubDate: 2017-12-18
      DOI: 10.1007/s00769-017-1305-5
       
  • Quality system implementation in the National Metrology Institute of
           Montenegro
    • Authors: Vanja Asanovic; Milena Raonic; Naina Cuturic-Knezevic; Goran Vukoslavovic; Milena Popovic; Vladan Jestrovic
      Abstract: Accreditation of calibration laboratories is a means for achieving competence recognition and assuring customers that their calibration services are accurate and reliable. Moreover, it is a powerful tool for a National Metrology Institute (NMI), enabling the formal acceptance of its measurement results. It could be especially useful when calibration activities are performed in well-developed laboratories, which have participated successfully in interlaboratory comparisons but have been awaiting the publication of Calibration and Measurement Capabilities in the BIPM Key comparison database. This paper describes establishment and implementation of a quality management system in the NMI of Montenegro called Bureau of Metrology (MBM) that complies with ISO/IEC 17025. We have presented the results of the first audit evaluation, corrective actions, preparation of quality management documentation, measurement traceability, as well as advantages of being accredited. Our experience of implementing ISO/IEC 17025 for the accreditation of national calibration laboratories established within the MBM shows that strategic planning, establishment of long-term objectives, as well as the commitment to fulfilling standard requirements are the basis for acceptable calibration results. International acceptance of confidence and reliability of calibration services and measurement results provided by the MBM laboratories represents a useful marketing tool for promoting the image of the institution.
      PubDate: 2017-12-04
      DOI: 10.1007/s00769-017-1303-7
       
  • The hitherto non-included component in the uncertainty budget for
           gravimetric measurement of particulate matter concentration in a conduit
    • Authors: Przemysław Kateusz
      Abstract: This article discusses the accuracy of the gravimetric measurement method of total particulate matter concentration in waste gases where the basic assumption is that sample collection of dust-laden gas is done in a grid with a finite number of points in the conduit’s measurement plane. In this standard approach, the sample is assumed to be representative for dust-laden gas in the conduit, and consequently, the total particulate matter concentration measured for the sample is considered the mean concentration in the conduit. The article investigates this assumption against the standard-imposed number of sampling points and in view of spatial distributions of particulate matter concentration in industrial plants which—being continuous—are not identified in measuring practice. Possible distributions were simulated both for particulate matter concentration and for gas velocity in rectangular conduits, and the following were calculated: (a) an accurate mean particulate matter concentration in the measurement plane, based on its definition employing continuous distributions of particulate matter concentration and gas velocity and (b) the concentration in a sample, i.e. measured concentration. Measurement deviation between those concentrations was determined, which is specific for cumulative gas sampling. Using the obtained set of possible deviations, an estimation method was suggested for the relevant uncertainty component of the gravimetric method, which so far has not been taken into account in the industrial measurement accuracy analyses. It turns out that the level of this uncertainty component for measuring the mean particulate matter concentration in the conduit (resulting from “measurement discretization”) is not to be ignored.
      PubDate: 2017-12-04
      DOI: 10.1007/s00769-017-1302-8
       
 
 
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