Metrological Assurance of Gas Calorimeter and Wobbe Index Analyser

The paper describes research on metrological assurance of such measuring instruments as gas calorimeters and Wobbe index analysers. The purpose of the performed research is development of reference materials for gases with certified value of net volume-basis calorific value traceable to Russian state primary standard. Input set of candidate gases is hydrogen, methane, ethane and propane, as well as the target uncertainty of lower volumetric combustion energy value equal to 0,3 % – both were selected basing on results of metrological characteristics analysis of calorimetric equipment. The certified value of lower volumetric combustion energy is traceable to the State Primary Standard of combustion energy, specific combustion energy and volumetric combustion energy units GET 16. The certified value of selected gases and the uncertainty of this value were estimated with usage of comparing calorimeters for the combustion of high- and low-calorie gases «USVG» and «USNG» included in GET 16. Results obtained during investigational study and reference materials characterisation confirmed the stated accuracy. The continuance in prospect may allow development of reference materials for gas imitating mixtures of natural and casing-head gases as well as include Wobbe index in the list of certified characteristics.

Development of food industry metrological assurance complex

The paper considers the contribution of experts from the Laboratory of Metrology of Moisture Measurement and Reference Materials to the improvement of the food industry metrological assurance system. The information on the results of the development of forty types of reference materials (RM) for the composition of various nutrition, food staples and nutritional supplement in the period 2008-2020 is generalized. The development of each new RM type included preparation of the material, research for its stability and homogeneity, and determination of certified value with the appliance of State primary (GET 173) and secondary (GVET 176-1) standards, as well as primary reference measurement procedures and conducting the interlaboratory experiment for checking the applicability of the RM. The creation in 2008 of GET 173 was accompanied by the development of RMs for the composition of grains and dry milk product. The approval in 2010 of GVET 176-1 allowed to add in the RM the certified value for the mass fraction of nitrogen (protein). As a result of successful participation in comparisons, UNIIM got 6 items of calibration and measurement capabilities on measurements of mass fraction of nitrogen in glycine, milk powder, grain, egg powder, cereal and feed-stuff in the BIPM database. 35 types of RM for the composition of dairy and meat products, egg powder, infant food, oil and starch products together with the development of primary reference measurement procedures for measurement of fat, crude fat, ash and carbohydrates mass fraction were created between 2016 and 2019. Moreover, the RM for the composition of nutritional supplement (glycine, melamine, cystine) and dairy products for metrological assurance of IR-analysers as well as RM for the composition of reconstituted milk were developed for the control of measurement results by the enzyme-linked immunosorbent assay (ELISA). Developed RM were systemized on fields of the appliance of Technical regulations of Customs Union and the sectors of the international food triangle model. These RMs allow providing the measurement uniformity of the identification indicators and the nutritional value of food products and food staples.

Reference materials for optic nanosensor systems: reduced glutathione and chloramphenicol

The research provides enterprise reference material (ERM) development approach for nanosensor system on the basis of dynamic light scattering and fluorescence for qualitative and quantitative determination of nutrition pollutant - chloramphenicol antibiotic (laevomycetin), as well as marker of ischaemic stroke and a number of other diseases - reduced glutathione.ERM candidate materials were chosen chloramphenicol and reduced glutathione. The attestation procedure based on calculating-experimental approach by preparation procedure was used to determine the certified value of ERM. During the tests there were determined metrological characteristics of reference material. The certified value of ERM for reduced glutathione mass fraction is 98,5 %, the expanded uncertainty of certified value with coverage factor k=2 is ± 0,3 %. The certified value of ERM for chloramphenicol mass concentration is 10,0 g/dm3, the expanded uncertainty of certified value with coverage factor k = 2 is ± 4,0 %.The implementation of the developed ERMs showed their appropriateness for optic nanosensor systems calibration on the base of dynamic light scattering and fluorescence.We suppose that the developed enterprise reference materials further may be certified as CRM (certified reference material) and used for verification, calibration and graduation of compact detection devices of the «point of care diagnostics» type under development, which are intended for express analysis on the sampling site directly.

Evaluation of image distortion in SEM by using a dot-array–based certified reference material

This paper presents a quick and straightforward method to evaluate image distortion in scanning electron microscopy using a certified reference material (CRM) as a test specimen. The CRM has a square dot-array structure, whose dot-pitch has an accredited value. By calculating the distance between each dot of the CRM via image analysis, we can detect the distortion in the image as variations of dot interval. Furthermore, by considering the uncertainty of the certified value, it is possible to quantitatively evaluate the significance of the distortion in the image. This method enables us to easily estimate the uncertainty from image distortion, which can improve the reliability of measurement by scanning electron microscopy.

243Am certified reference material for mass spectrometry

The Joint Research Centre, in cooperation with the Commissariat à l’Energie Atomique et aux Energies Alternatives, produced a novel 243Am spike reference material for mass spectrometry. Americium solution with an isotopic composition of 88% 243Am and 12% 241Am was used as the source for the preparation of the spike material. The certified value of 5.696 (11) nmol g−1 for the amount content of 243Am and 0.136138 (54) for the n(241Am)/n(243Am) amount ratio were assigned. The assigned values from mass spectrometry were confirmed by alpha-particle spectrometry, alpha-particle counting at a defined solid angle, and high-resolution gamma-ray spectrometry. Furthermore, an external validation of the certified values was obtained from the results of an interlaboratory comparison exercise, using this americium reference solution as the test sample.

Certification of sodium benzoate solution reference material by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometry for food and drug analysi

Sodium benzoate is one of the most widely used food perseverates and has to be used in regulated amounts to avoid its harmful health effects. Reviewing the scientific literature for traceability of the analytical measurement results of sodium benzoate in various food and drug applications to the SI units, it has been found that no scientific details of certification of sodium benzoate CRMs used for the calibration of measuring equipment are published. For this reason, the national metrology institute of Saudi Arabia (SASO/NMCC) certifies a sodium benzoate solution reference material. In this work, sodium benzoate was synthesized, purified and a batch solution reference material was prepared as 1014.47 mg/kg then homogenized and bottled. Homogeneity and stability of the candidate RM were assessed and the results obtained showed that the material is sufficiently homogeneous and stable. Characterization of the reference material was carried out by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer as three independent methods. The certified value was derived by combining data from the three methods using the weighted mean approach and was found 1016.13 mg/kg. The certified uncertainty was calculated as weighted uncertainty and was found 10.47 mg/kg (1.03%). Sources of this uncertainty were identified from the characterization, uchar, homogeneity, uhom, and long-term stability, ults, as well as the bias allowance, B.

Certification of SRM 640f line position and line shape standard for powder diffraction

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to be used to evaluate specific aspects of the instrument performance of both X-ray and neutron powder diffractometers. This report describes SRM 640f, the seventh generation of this powder diffraction SRM, which is designed to be used primarily for calibrating powder diffractometers with respect to line position; it also can be used for the determination of the instrument profile function. It is certified with respect to the lattice parameter and consists of approximately 7.5 g of silicon powder prepared to minimize line broadening. A NIST-built diffractometer, incorporating many advanced design features, was used to certify the lattice parameter of the Si powder. Both statistical and systematic uncertainties have been assigned to yield a certified value for the lattice parameter at 22.5 °C of a = 0.5431144 ± 0.000008 nm.

Certification of Standard Reference Material 660c for powder diffraction

The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to evaluate specific aspects of instrument performance of both X-ray and neutron powder diffractometers. This report describes SRM 660c, the fourth generation of this powder diffraction SRM, which is used primarily for calibrating powder diffractometers with respect to line position and line shape for the determination of the instrument profile function (IPF). It is certified with respect to lattice parameter and consists of approximately 6 g of lanthanum hexaboride (LaB6) powder. So that this SRM would be applicable for the neutron diffraction community, the powder was prepared from an isotopically enriched 11B precursor material. The microstructure of the LaB6 powder was engineered specifically to yield a crystallite size above that where size broadening is typically observed and to minimize the crystallographic defects that lead to strain broadening. A NIST-built diffractometer, incorporating many advanced design features, was used to certify the lattice parameter of the LaB6 powder. Both Type A, statistical, and Type B, systematic, uncertainties have been assigned to yield a certified value for the lattice parameter at 22.5 °C of a = 0.415 682 6 ± 0.000 008 nm (95% confidence).

Sum-peak method with two NaI(Tl) crystals: 68(Ge+Ga) standardization

A 68(Ge+Ga) commercial solution has been standardized in LNMRI in Brazil, by sum-peak method, in which a 3”x3” NaI(Tl) gamma-ray detector is positioned at the top of a well-type 5”x5” NaI(Tl) gamma-ray detector, resulting in a set up approximately 4p geometry. In this work the known germanium volatility was tested using three dried sources and three liquid sources in the sum-peak method measurements and the activity results showed a standard deviation of 0.41%. The activities were compared with another primary method: 4pb-g live-timed anti-coincidence counting. The two methods gave activity concentration values with differences from the certified value of +0.8 % (anticoincidence method) and -3.4% (sum-peak method).