The article presents the results of applying gas chromatography - mass-spectrometry (GC-MS) and tandem mass spec-trometry (GC-MS/MS) methods for determination of certified values (mass fraction) of «Dioxins» - Polychlorinated Dibenzo-p-dioxins and Dibenzofurans (PCDD/PCDF) in animal fat. It has been established that the using of tandem mass-spectrometry makes it possible to reduce the Limit of Detection and Limit of Quantification of the congeners an order of magnitude and also it significantly improves the accuracy of the CRM. As a result, the certified values of PCDF congeners were determined in the range from 0,5 to 850 ng/kg and PCDD congeners in the range from 0,5 to 2 ng/kg. The relative expanded uncertainty of the certified values by using the GC-MS/MS does not exceed 7 %. Thus, the CRM of PCDD/PCDF in animal fat was developed for the purpose of validation, verification of measurement procedures and quality control of measurement results.
The article is devoted to the development of a reference material of chlorobenzene composition, providing metrological traceability of measurement results to the State primary measurement standard of units of mass (molar) fraction and mass (molar) concentration of organic components in liquid and solid substances and materials based on liquid and gas chromatography-mass spectrometry with isotopic dilution and gravimetry GET 208-2014.The paper considers an indirect method for determining the purity of the starting substance, describes the main stages of development of the reference material, and presents the results of the evaluation of the reference material metrological characteristics, including studies on homogeneity and stability.The reference material of the composition of chlorobenzene has the following metrological characteristics: mass fraction of chlorobenzene (from 993.0 to 999.8 mg/g); molar fraction of chlorobenzene (from 99.30% to 99.98%); the expanded uncertainty of the certified characteristics is 0.02% (at k = 2).The reference material ensures metrological traceability to units of measuring instruments and measurement results, and is intended for verification, and calibration and graduations.
The article is devoted to the development of a reference material of the sorption roperties of nanoporous zeolite, which ensures metrological traceability of measurement results to the State primary measurement standard of units for specific gas adsorption, specific surface area, specific pore volume, pore size, open porosity and gas permeability coefficient of solid substances and materials GET 210-2019.The paper presents the results of theoretical and experimental studies on optimizing the conditions of sample preparation (thermal training) of the reference material using the thermogravimetric method and differential scanning calorimetry, coupled with mass spectrometric detection of the evolved gases (TG-DSC–MS analysis). The results of establishing the metrological characteristics of the reference material are described, including standard uncertainty due to the method of determining the certified value, as well as standard uncertainties from heterogeneity and instability. The GSO 10734–2015 reference material of the sorption properties of nanoporous zeolite (Zeolite SO UNIIM) has certified metrological characteristics: specific surface area (500–1200) m2/g; specific pore volume (0.10.5) cm3/g; the predominant pore diameter (0.4–0.9) nm; specific argon adsorption (0.001–20.0) mol/kg.The reference material is designed to calibrate measuring instruments and to control accuracy of results of sorption characteristics of nanoporous materials measurements; it can be used to certify appropriate measurement procedures, to test measuring instruments and reference materials for type approval and other types of metrological control.
This article is devoted to improving the state primary special standard of the pressure unit for the pressure difference of the GET 95-75. The article describes the stages and results of work to improve the standard.
In this article, the author proposed a method for estimating the consensus value of interlaboratory measurement results, which makes it possible to reduce the estimation uncertainty in comparison with the known methods. The method is based on the selection in the inconsistent data of the largest consistent subset of the results, the uncertainties of which do not increase when calculating the consensus value.
Процедура продления срока действия свидетельств об утверждении типов стандартных образцов осуществляется Росстандартом на основании заявок, поступающих от изготовителей стандартных образцов, держателей свидетельств об утверждении типов стандартных образцов. По результатам рассмотрения указанных заявок принимается решение, оформленное в виде приказа Росстандарта «О продлении срока действия свидетельств об утверждении типов стандартных образцов». В случае принятия положительного решения по продлению срока действия свидетельств изготовителям выдают свидетельства об утверждении типов стандартных образцов нового срока действия. Для стандартных образцов, форма выпуска которых – серийное производство, срок действия свидетельств продлевают на последующие пять лет. Для стандартных образцов, выпущенных единичными партиями, устанавливают срок действия свидетельств, соответствующий сроку годности экземпляров стандартных образцов. Стандартные образцы, срок действия свидетельств которых продлен в первой половине 2018 г., представлены в табл. 1.
The authors present experimental data on the development of a special sample in the form of a dispersed material that simulates the mineral macro-component composition of natural surface water. The results of the study obtained by a number of physico-chemical analysis methods were compared to determine the mass concentration of the micro-component - manganese (II) in the sample. Determination of the mass concentration of manganese (II) was carried out by the methods of spectrophotometry for PND F 14.1:2.61, x-ray fluorometry for PND F 14.1:2:4.130, inversion voltammetry for PND F 14.1:24.217.Procedures for establishing the metrological characteristics of a special sample to control the accuracy of the results of measurements of the mass concentration of manganese (II) using a number of physicо-chemical analysis methods have been carried out.A number of advantages and disadvantages of certified measurement methods that are widely used in chemical laboratories for determining the content of manganese in natural surface water are noted. The necessity of carrying out the procedure of certification of the spectrophotometric method with the use of manganese (II) ions - sodium periodate as an oxidizer is shown.
The article provides an analysis of accuracy indicators for measuring the alcohol by volume (ABV) in vodka performed by various methods according to GOST 32035–2013 «Vodka and Special Vodka. Acceptance Rules and Methods of Anlysis». The results of two rounds of the interlaboratory comparisons on determination of the ABV in vodka conducted to verify the qualifications of accredited testing laboratories are described.Information is provided on the development of the GSO 11142–2018 reference material for the volume fraction of ethanol in an aqueous solution (VER-2), certified for the volume fraction of ethanol in an aqueous solution, instances of which were used during the interlaboratory comparisons. The conclusion is made about the satisfactory quality of measurements of ABV in vodka in the accredited laboratories.
For the metrological assurance of the high-precision inductively coupled plasma (ICP) mass spectrometry and optical emission spectroscopy methods, the All-Russian Scientific Research Institute for Optical and Physical Measurements (VNIIFTRI) has launched works on the development of reference materials (RMs) of the mass fraction of metals in solutions specifically intended for measurements using inductively coupled plasma methods (ICP-CRM). The ICP-CRM under development was represented by a solution with the certified value of the lead mass fraction. The ICP-CRM was packed in high-density polyethylene bottles with the capacity of 4, 8, 15, 30, 60 and 125 cm3. The certified value of the lead mass fraction in the solution was established by the preparation method and confirmed by the GET 217-2018 State Primary Standard for units of the mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods. The permissible certified values of the lead mass fraction in the developed ICP-CRM are shown to range from 800 mg / kg to 1200 mg / kg. The uncertainty in the certified value is expressed as expanded uncertainty, U = 0,5 % at 95 % confidence, and is calculated in accordance with ISO/IEC 17025 according to GUM (Guidelines to Uncertainty in Measurement). The developed ICP-CRM solution of the lead mass fraction can be used for ensuring the metrological traceability of measurements in inorganic analyses using ICP-MS and ICP-OES to the GET 217-2018.
This paper describes measurement techniques, structure, technical characteristics and results of the uncertainty analysis for primary multifunction power standard in the frequency range from 1 Hz to 2500 Hz.
The authors provide information on the need to develop a reference material (RM) of the southern middle loamy black soil certifiedfor fertility indicators. The information about the stages of RM development is described: selection and preparation of soil material in the field; procedure of averaging soil material.In the determination of the RM metrological characteristics, the heterogeneity and stability characteristics of the RM are evaluated.The authors demonstrated the results of the RM certification for agrochemical indicators. The correctness of these results is confirmed by the results obtained in twenty-three accredited laboratories.The developed RM is registered in the State Register of the Approved Types of Certified Reference Materials under the number GSO 11369-2019-the RMfor composition (of agrochemical indicators) of the southern middle loamy black soil (SACHyuzhP-02).The RM is intended for metrological support of agroecological monitoring of agroindustrial complex laboratories.
This article is timed to coincide with the end of the celebration of the International Year of the Periodic Table of Chemical Elements, declared by the UN and UNESCO in connection with the 150th anniversary of the discovery by D. 1. Mendeleev of the Periodic Law of Chemical Elements. The article highlights metrological activity of the great Russian scientist and encyclopedist and tells about how in the scientific metrological centre, he created- the Main Chamber of Weights and Measures, now D. 1. Mendeleev VNllM (VNllM), the memory of the life and activities of the first administrator of the Main Chamber of Weights and Measures Weights has been preserved for more than a hundred years. Based on research, carried out in the archives of St. Petersburg and the funds of Metrological Museum, the article for the first time details the history of the formation of the Mendeleev memorial complex on the territory of VNIIM. The contribution of the institute metrologists to the creation of such famous sights of St. Petersburg as the monument to D. 1. Mendeleev (the work of the sculptor 1. Ya. Ginzburg, 1932) and the mosaic panel « D. 1. Mendeleev Periodic system of elements «(1935) on the occasion of the 100th anniversary of the scientist is shown. All peripetias, related to the installation of the monument table are described: selection of options for the arrangement of elements, decoration, manufacturer and manufacturing techniques, coordination with various organizations, solving financing issues.
The article presents the results of creating a new state primary standard for the specific heat capacity unit and means for transmission of the unit to other devices, namely, reference measures from various materials. The main structural features of the created calorimeter, its metrological characteristics are described. The data on the specific heat capacity of some materials, considered as the reference measures of specific heat, are shown. The experimental data are compared with data, published by other researchers.
The article covers different aspects of the life of the All-Union D. I. Mendeleev Institute for Metrology (VNIIM) during the years of the Great Patriotic War: history of evacuation of part of measurement standards and laboratories and creation of VNIIM’s filial branch in Sverdlovsk in April 1942, personnel appointments caused by the wartime condi-tions, activities of the Science Council of VNIIM in the Sverdlovsk Filial and sieged Leningrad. The factors are reflected that allowed to organize in the siege winter of the 1941-1942 years work of a number of laboratories including the reference and the tower clocks and to save lives of many employees: the precise work of the Local Air Defence, the obtaining of electric energy due to the placing of radio-transmitter for connection with the Big Land, accommodation of employees on the territory of the Institute etc. The article also tells about keeping the memory of the wartime events in VNIIM and the institute employees that fell on the front and during the siege. The article was written on the base of investigations made in archives of Saint-Petersburg and memories of VNIIM employees, that are stored in the funds of the Metrological Museum. The article is timed to the 75th anniversary of the Victory in the Great Patriotic War.
The article puts forward the concept of strain, the strain measurement units, means, methods and specifics of strain measurement. The round of interlaboratory comparisons in the field of measuring strain by determining the characteristics of tensoresistors with the help of pure bending installations. The results of the round, the analysis and the conclusions are presented.
