Metrological traceability of measurement results and calibration hierarchy is a prerequisite for improved data compatibility: example of the VPDB scale.

<p>For stable isotope data sets to be compared or combined in biogeochemical studies, their compatibility must be well understood. For δ13C measurements in greenhouse gases, the WMO GAW program has set compatibility targets of 0.010 ‰ for atmospheric CO2 and 0.020 ‰ for atmospheric methane (in background air studies [1, 2]). The direct comparison of samples between laboratories can provide limited information, such as a snapshot for a specific time period, but combining data sets produced over decades requires more efforts. To produce high quality data, reliable calibrations must be made, mutually consistent values of reference materials (RMs) must be used, and a traceability scheme that ensures low uncertainty must be implemented.</p><p>The VPDB δ13C scale provides example of approaches developed recently. Several problems with the existing implementation of the VPDB scale have been identified between 2009-2016 [3]: the primary reference material (RM) NBS19 was exhausted and needed to be replaced; the δ13C of LSVEC (used to anchor the VPDB scale at negative δ13C) was found to be drifting and its use as a RM for δ13C was discontinued [4]; other RMs that were available in 2016 (e.g., NBS18) were not able to be used to develop new RMs as their uncertainties were too large. Given that the VPDB scale is artefact-based and not supported by absolute ratio measurements with uncertainty as low as required, the principles of value assignments on the VPDB scale were needed to be revised.</p><p>To ensure that a revised scheme did not encounter similar problems (with dependence on a single scale-anchor), several fundamental metrological principles were considered: (i) traceability of measurement results to the primary RM, (ii) a hierarchy of calibrators and (iii) comprehensive understanding of measurement method(s) [5]. The revised VPDB scheme [3] was applied to the new primary RM [6] and three RMs covering a large δ13C range (to negative values) [7]. Values were assigned in a mutually consistent way, with uncertainties ranging from 0.010 to 0.015 ‰, depending on the assigned δ13C. Each RM value has an uncertainty assigned that includes all known instrumental corrections, potential alterations due to storage, and inhomogeneity assessment [6,7]. The scheme allows for the δ13C range to be expanded by developing new carbonate RMs, and to be extended to matrix-based RMs.</p><p>The revised VPDB δ13C scale realization should lead to a robust basis for improving data compatibility. The developed framework can be applied to other measurements of biogeochemical interest, such as small 17O variations (in H2O, carbonates and other samples), clumped isotopes, and various paleoclimate reconstructions. Notably, the traceability principle is helpful in realistic uncertainty estimations which provide a tool to understand constrains and limiting steps in data comparisons.</p><p>REFERENCES:  [1]. WMO, GAW Report No.229. 2016. [2]. WMO, GAW Report No.242. 2018. [3]. Assonov, S. et al., RCM, 2021. https://doi.org/10.1002/rcm.9018. [4]. IUPAC, Press release of the IUPAC meeting in 2017, https://iupac.org/standard-atomic-weights-of-14-chemical-elements-revised/. [5]. De Bievre, P. et al., PURE APPL CHEM, 2011. <strong>83</strong>(10): p. 1873-1935. [6]. Assonov, S., et al., RCM, 2020: p. https://doi.org/10.1002/rcm.8867. [7]. Assonov, S. et al., RCM, 2021. https://doi.org/10.1002/rcm.9014</p>

Creatinin in the modern evaluation of the kidneys functional condition (literature review and own data)

Glomerular filtration rate (GFR) is a recognized indicator of the functional status of the kidneys. In medical practice, there are various approaches for measuring GFR. However, despite the nearly 100-year history, not all methodological problems of evaluating GFR in clinical practice have been solved. The most physiologically justified (“reference”) methods are not acceptable in routine practice because of the complexity and high cost. Therefore, clinicians have to rely mainly on the results of surrogate methods, most of which use endogenous creatinine as a glomerulotropic test agent. Therefore, the accuracy of determining the concentration of this metabolite in biological media (especially in serum) is often crucially determined by the reliability of the GFR assessment. Manufacturers of creatinine reagent kits should take into account current requirements for accuracy and traceability of measurement results and ensure that their products comply with international standards.

Problems of ensuring the uniformity of blood pressure measurements

The problems of ensuring the unity of non-invasive blood pressure measurements are considered. It is shown that the artery and surrounding tissues of the body serve as a means of comparing the values of blood pressure and air pressure in the cuff, and that the metrological traceability of measurement results to pressure standards only partially determines the reliability of these results. The potential possibilities of the surface pulse wave method in comparison with the Korotkov tone method are estimated.

In Memoriam: René Dybkaer

I first met René when the IUPAC General Assembly came to Brisbane Australia in 2001. IUPAC was not an organization I (then) knew much about, but I found myself confronted by Paul De Bièvre demanding that I join a task group on metrological traceability. At the time I would not have called myself a metrologist in chemistry (MiC) or in any other field. The great minds assembled for the project were Paul De Bièvre, René Dybkaer, Ales Fajgelj, and me. I had no idea that our task would take ten years (finally published as De Bièvre, P.; Dybkaer, R.; Fajgelj, A.; Hibbert, D. B.: Metrological traceability of measurement results in chemistry: Concepts and implementation (IUPAC Technical report) Pure Appl. Chem. 2011, 83, 1873-1935), and that during the time I would come to form strong friendships with my comrades in the “Gang of Four.” Paul is no longer with us and now René has left the stage.

The requirements of the international standards on traceability of measurement results at OJSC «BSW – Management Company of Holding «BMC»

A serious barrier to the sale of products on the market is the trust in organizations that perform measurements during product testing, as well as calibration (verification) of the used measuring instruments. Confidence and recognition of measurement results at the international level is ensured through an accreditation mechanism. To ensure effective functioning at the international level, accreditation organizations enter into a multilateral agreement that provides for the use of common standards in the conduct of accreditation. One of the important requirements of these standards is the implementation and demonstration of metrological traceability, which is a tool for ensuring the uniformity of measurements.

Experience of using atomic-emission spectrometers with MAÉS in an accredited laboratory

A system of the set rules, procedures and regulatory documents is developed in the Central Analytical Laboratory of the JSC «EZ OCM» for the method of atomic emission spectral analysis of precious metals with arc excitation of the spectrum to meet all the requirements of the accrediting body «Rosakkreditatsiya». The features of managing the measuring instruments — spectrometers with MAÉS analyzers, auxiliary equipment and microclimate are considered. The requirements to the personnel of the laboratory for spectral analysis are considered. The rules for developing measurement procedures, instructions for laboratory technicians, measuring programs, methods for performing routine analysis of the samples, and ensuring the traceability of measurement results are specified. The availability of using «ATOM3.3» software for solving everyday problems of the laboratory is shown.

Reference materials of catalytic activity as a means of ensuring the metrological traceability of measurement results. KATAL

Introduction. The article considers the problems of metrological support of catalytic activity measurements. The paper gives certain characteristics of the State Primary Special Measurement Standard for the unit of catalytic activity – KATAL and examines the role of reference materials (RMs) in ensuring the metrological traceability of measurement results.Materials and methods. A method for measuring the concentration of the recombinant protective antigen of Bacillus anthracis and the recombinant GP-protein of the Ebola virus, which means in using «sandwich» enzyme-linked immunosorbent assay, was certified by FGUP «VNIIMS» as a measurement procedure. The following RMs tested by FGUP «VNIIMS» can be used for the development and production of appropriate control samples when performing measurements for comparisons: the RM for the mass concentration of the recombinant protective antigen of Bacillus anthracis in phosphate-saline solution, the RM for the mass concentration of the recombinant GP-protein of the Ebola virus, and the RM for the mass concentration of recombinant Clostridium Difficile toxin.Results. The paper presents the main reactions of the method for measuring the catalytic activity of catalysts for heterogeneous processes, which are also used to carry out exhaust gas cleaning processes.Discussion and conclusions. Thus, conditions have been created for building hierarchies of calibrations of in-demand objects established on the basis of the List of Critical Technologies of the Russian Federation, state programs for the development of industrial sectors.