Metrologické aspekty v analytické chemii: stanovení kovů ve vodách

The monitoring of water quality in the EU is described in detail and regulated by Directives of the European Commission and the Parliament, which underlines the importance of the quality of water (both potable and non-potable). Analysis of trace concentrations of contaminants in water, including metals, still presents challenges to demonstrate the quality and comparability of results. The article provides a detailed overview of the procedures that laboratories can use to assess the reliability of the results obtained by a particular measurement procedure. Emphasis is placed on three basic pillars: metrological traceability, validation and measurement uncertainty. Subsequently continuous evaluation is carried out using internal and external quality management measures. Regional aspects specific for the Czech Republic are also mentioned.

Application of systems thinking to the establishment of metrological traceability chains

International agreements in the field of metrology and accreditation of calibration laboratories are the basis for establishing global metrological traceability. Important elements of metrological traceability are calibration of measurement standards and measuring instruments, assessment of measurement uncertainty. The International Laboratory Accreditation Cooperation has a specific policy regarding on traceability of measurement results and estimation of measurement uncertainty in calibration. The partial concept diagram around metrological traceability in accordance with the International Vocabulary of Metrology is proposed. This diagram contains a total of nine metrological concepts, which have most of the associative relations. There are associative relations between the concept of metrological traceability chain and concepts of metrological traceability, measurement standard, calibration and calibration hierarchy, and through the concept of measurement standard with the concept of measurement uncertainty. Systems thinking to the analysis of state of proposed terminological system around metrological traceability was applied. For construction of generalized metrological traceability chain, all the established properties of the system elements around the terminology system of metrological traceability were taken into account. Generalized metrological traceability chain for different levels of the calibration hierarchy was proposed. The proposed chain can be used to develop appropriate chains for specific areas of measurement. To achieve this, it is necessary to determine the specific measured value, the required measurement uncertainty for different levels of the calibration hierarchy and select the necessary measurement standards. Such schemes should be used in national metrology institutes and calibration laboratories.

Development of Genistein Synthesis for Use as a Certified Reference Material

Introduction. The use of certified reference materials (CRMs) ensures metrological traceability and comparability of analysis results performed in different laboratories, by different analysts, at different times. Genistein is a promising substance with a wide spectrum of pharmacological action. genistein is widely used in dietary supplements. Development of regulatory documents for CRM of genistein will ensure the quality of drugs and dietary supplements.Aim. Aim of our study is to improve of the ways of synthesis and determination of spectrum characteristics of genistein for the certification of CRM.Materials and methods. We used synthetic genistein, (Ph.D. V. Yu. Kovtun SPC "Pharmzashchita") (sample № 1) and genistein synthesized and studied at the departments of pharmaceutical chemistry and chemical technology of medicinal substances SPCPU (sample № 2). Infrared spectra of genistein samples were collected on an FSM 1201 infrared Fourier spectrometer (OOO Infraspek, Russia) via KBr pellets technique. All the spectra were collected in the 4000–500 cm−1 range. The NMR (1H and 13C) measurements were performed with a BrukerAvance III NMR spectrometer (400 and 100 MHz) (Bruker, Germany) in DMSO-d6 solvent. Raman spectra were recorded by an ORTES-785TRS-2700 analytical Raman scattering system at a laser power of 100 mW (OPTEC JSC, Russia). Laser interaction time was 5, 10, 20 and 60 seconds. The results were processed using the software "BWSpec 4.10_4", USA. GC-MS was performed on an Agilent Technologies 7890A gas chromatograph (Agilent Technologies, USA) with a 7693 autoinjector and a Hewlett Packard 5975C mass selective detector.Results and discussion. The synthesis was carried out according to the developer's method. The stage "removal of the alkyl protection" has been improved. The spectra of the synthesis intermediate of genistein (biochanin A) correspond to the literature data. Samples of genistein were investigated by methods: MC and NMR 13С, 1Н. The structure of the investigated substance was confirmed; Raman and IR spectroscopy showed that the spectra of the samples do not differ from each other and there are no additional signals.Conclusion. The spectrum characteristics of samples of genistein were obtained by NMR, IR and Raman spectroscopy, which will be used in the regulatory documentation for CRM of genistein. All of this will make it possible to control the quality of medicines based on it and to identify substandard dietary supplements.

The Metrological Traceability, Performance and Precision of European Radon Calibration Facilities

An interlaboratory comparison for European radon calibration facilities was conducted to evaluate the establishment of a harmonized quality level for the activity concentration of radon in air and to demonstrate the performance of the facilities when calibrating measurement instruments for radon. Fifteen calibration facilities from 13 different European countries participated. They represented different levels in the metrological hierarchy: national metrology institutes and designated institutes, national authorities for radiation protection and participants from universities. The interlaboratory comparison was conducted by the German Federal Office for Radiation Protection (BfS) and took place from 2018 to 2020. Participants were requested to measure radon in atmospheres of their own facilities according to their own procedures and requirements for metrological traceability. A measurement device with suitable properties was used to determine the comparison values. The results of the comparison showed that the radon activity concentrations that were determined by European calibration facilities complying with metrological traceability requirements were consistent with each other and had common mean values. The deviations from these values were normally distributed. The range of variation of the common mean value was a measure of the degree of agreement between the participants. For exposures above 1000 Bq/m3, the variation was about 4% for a level of confidence of approximately 95% (k=2). For lower exposure levels, the variation increased to about 6%.

Research and Development of Metrological Assurance Elements for Leeb Hardness Measurements

This article is devoted to contemporary topics of ensuring the uniformity of Leeb hardness measurements. The analysis of the physical principles of the Leeb hardness test is carried out, and the influence of the measuring transducer parameters on the measurement results is investigated. A four-level structure of the calibration hierarchy for the Leeb hardness scales is proposed, which ensures metrological traceability of hardness scales from the calibration reference machines (CRMs) to measuring instruments. A list of requirements for the 2nd grade CRM and the 2nd grade Leeb reference test blocks are formulated in accordance with the proposed calibration hierarchy draft and their values are calculated. A prototype was developed and a model of the 2nd grade Leeb hardness CRM and a set of Leeb reference test blocks were manufactured, as well as the compliance of their metrological characteristics with the requirements of the proposed calibration hierarchy draft and international standards was confirmed. The results of this work allow us to ensure the uniformity and reliability of the Leeb hardness measurements.

Metrological support of phthalate content measurements: reference material for the composition of a solution of six priority phthalates in methanol

The article provides information on the development of a new reference material (RM) for the composition of a solution of six priority phthalates (dimethyl phthalate, diethyl phthalate, di(n-butyl) phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, di(n-octyl) phthalate) in methanol provided with metrological traceability to GET 208-2019 (GET 208). The procedure for the preparation and certification of RMs is shown, including the estimation of homogeneity and stability. Pure organic substances (phthalates) characterized on GET 208 were used as the starting material for the RM. The RM material was prepared by weight and volume-weight methods. The stability study of the RM was carried out by the isochronous procedure. The RM certified values are the mass fraction and mass concentration of individual phthalates in the solution. When calculating the uncertainty budget for RM certified values, contributions from the purity of the starting materials, RM preparation procedures, heterogeneity, and long-term instability were taken into account. The relative expanded uncertainty of the certified values does not exceed 2 %. As a result, a certified reference material (CRM) was developed and approvedfor the composition of a solution of ortho-phthalic acid esters (phthalates) in methanol GSO 11366-2019. The practical significance of the application of GSO 11366-2019 is to ensure the metrological traceability of RM to the corresponding SI units reproduced on GET 208. The developed CRM can be applied in resolving any measuring tasks and performing a full range of metrological works.

Optimizing Available Tools for Achieving Result Standardization: Value Added by Joint Committee on Traceability in Laboratory Medicine (JCTLM)

Background The JCTLM created a Task Force on Reference Measurement System Implementation (TF-RMSI) to provide guidance on metrological traceability implementation for the in vitro diagnostics (IVD) community. Content TF-RMSI investigated the reference measurement systems (RMS) for 13 common measurands by applying the following procedural steps: (a) extracting data from the JCTLM database of available certified reference materials (CRMs) and reference measurement procedures (RMPs); (b) describing the RMS to which each recruited CRM or RMP belongs; (c) identifying the intended use of the CRMs, and, if used as a common calibrator for IVD measuring systems and/or trueness assessment of field methods was included, checking the CRM’s certificate for information about commutability with clinical samples; and (d) checking if the CRM or RMP measurement uncertainty (MU) has the potential to be small enough to avoid significantly affecting the analytical performance specifications (APS) for MU of clinical sample results when the MU from the IVD calibrator and from the end-user measuring system were combined. Summary We produced a synopsis of JCTLM-listed higher-order CRMs and RMPs for the selected measurands, including their main characteristics for implementing traceability and fulfilling (or not) the APS for suitable MU. Results showed that traceability to higher-order references can be established by IVD manufacturers within the defined APS for most of the 13 selected measurands. However, some measurands do not yet have suitable CRMs for use as common calibrators. For these measurands, splitting clinical samples with a laboratory performing the RMP may provide a practical alternative for establishing a calibration hierarchy.