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1

Kasilyunas, Anastasia V., Maria Yu Medvedevskikh, Maria P. Krashenina, and Anna S. Sergeeva. "Key development stages of reference material for lactose monohydrate composition." Journal of Physics: Conference Series 2192, no. 1 (March 1, 2022): 012020. http://dx.doi.org/10.1088/1742-6596/2192/1/012020.

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Анотація:
Abstract The article mirrors key stages of development of reference material (RM) for the composition of lactose monohydrate with certified values of mass fraction of water and basic material. The RM could be used in the analytical chemistry and food industry, as well as at identification and assessment of nutritive products safety, int. al., infant food. The RM under development will be intended for metrological assurance of mass fraction of water and basic substance measuring instruments based on usage of thermogravimetric, titrimetric and chromatographic methods, certification of measurement procedures and control of measurement results of lactose monohydrate mass fraction accuracy, used as the host material, and in compositions of organic substances and materials or in measurements of water mass fraction in solid substances and materials, as well as for other kinds of metrological control. Determination of certified value of lactose monohydrate mass fraction in the RM was performed by reference method of iodometric titration and affirmed by mass balance method (one hundred minus the number of impurities) and by calculating-experimental method. The certified value of mass fraction of water was assigned by the Fischer’s method of volumetric titration and confirmed by the thermogravimetric method. Considerable attention was focused to the study of the separation process of sorbed and crystallisation water in a high-purity lactose monohydrate reagent. The results of measurements of the quantitative content of the types of water were considered when assessing the purity of the target substance by various methods. Unlike existing RM of similar composition, the traceability of the certified values of the RM being developed will be ensured to units of values reproduced respectively by the state primary (GET 173-2017) and secondary (GVET 176-1-2010) standards.
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2

Phillips, Melissa M., Tomás M. López Seal, Jennifer M. Ness, and Kai Zhang. "Development and Characterization of a Multimycotoxin Reference Material." Journal of AOAC International 102, no. 6 (November 1, 2019): 1642–50. http://dx.doi.org/10.5740/jaoacint.19-0109.

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Анотація:
Background: Matrix-matched reference materials (RMs) are critical for adequate quality assurance of extraction, digestion, separation, and/or detection processes for analytes of interest in foods and dietary supplements. The accurate determination of mycotoxins in foods is an international concern. While RMs for mycotoxins are available from a variety of RM producers, these mainly address a single mycotoxin or group of mycotoxins and therefore require the use of multiple RMs for multitarget methods. Objective: To address the increasing needs of laboratories moving toward LC-MS-based multimycotoxin analysis, the U.S. National Institute of Standards and Technology (NIST) collaborated with the U.S. Food and Drug Administration (FDA) to produce a naturally incurred RM for multiple mycotoxins in corn. Methods: Homogeneity of the RM has been assessed using a stratified random sampling of the final product based on mycotoxin mass fractions measured by the FDA and NIST. Multiple sample sizes were evaluated to maximize homogeneity in the obtained results. The mycotoxin levels in the final materials have been evaluated via interlaboratory comparison and isotope dilution LC–tandem MS measurements made at the FDA and NIST. The final value assignment combined results from these data sets. Conclusions: The study successfully developed a certified RM, SRM 1565 Mycotoxins in Corn, and a workflow for the future development of multimycotoxin RMs in different matrices.
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3

Phillips, Melissa M., Tomás M. López Seal, Jennifer M. Ness, and Kai Zhang. "Development and Characterization of a Multimycotoxin Reference Material." Journal of AOAC INTERNATIONAL 102, no. 6 (November 1, 2019): 1642–50. http://dx.doi.org/10.1093/jaoac/102.6.1642.

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Анотація:
Abstract Background: Matrix-matched reference materials (RMs) are critical for adequate quality assurance of extraction, digestion, separation, and/or detection processes for analytes of interest in foods and dietary supplements. The accurate determination of mycotoxins in foods is an international concern. While RMs for mycotoxins are available from a variety of RM producers, these mainly address a single mycotoxin or group of mycotoxins and therefore require the use of multiple RMs for multitarget methods. Objective: To address the increasing needs of laboratories moving toward LC-MS-based multimycotoxin analysis, the U.S. National Institute of Standards and Technology (NIST) collaborated with the U.S. Food and Drug Administration (FDA) to produce a naturally incurred RM for multiple mycotoxins in corn. Methods: Homogeneity of the RM has been assessed using a stratified random sampling of the final product based on mycotoxin mass fractions measured by the FDA and NIST. Multiple sample sizes were evaluated to maximize homogeneity in the obtained results. The mycotoxin levels in the final materials have been evaluated via interlaboratory comparison and isotope dilution LC–tandem MS measurements made at the FDA and NIST. The final value assignment combined results from these data sets. Conclusions: The study successfully developed a certified RM, SRM 1565 Mycotoxins in Corn, and a workflow for the future development of multimycotoxin RMs in different matrices.
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4

Miller-Ihli, N. J. "Characterization of a diet reference material (RM 8431)." Science of The Total Environment 71, no. 1 (April 1988): 105–7. http://dx.doi.org/10.1016/0048-9697(88)90303-8.

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5

Sharpless, Katherine E., and Lisa M. Gill. "Value Assignment of Nutrient Concentrations in Five Standard Reference Materials and Six Reference Materials." Journal of AOAC INTERNATIONAL 83, no. 2 (March 1, 2000): 413–24. http://dx.doi.org/10.1093/jaoac/83.2.413.

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Анотація:
Abstract A number of food-matrix reference materials (RMs) are available from the National Institute of Standards and Technology (NIST) and from Agriculture Canada through NIST. Most of these materials were originally value-assigned for their elemental composition (major, minor, and trace elements), but no additional nutritional information was provided. Two of the materials were certified for selected organic constituents. Ten of these materials (Standard Reference Material® [SRM] 1563 Cholesterol and Fat-Soluble Vitamins in Coconut Oil [Natural and Fortified], SRM 1566b Oyster Tissue, SRM 1570a Spinach Leaves, SRM 1974a Organics in Mussel Tissue (Mytilus edulis), RM 8415 Whole Egg Powder, RM 8418 Wheat Gluten, RM 8432 Corn Starch, RM 8433 Corn Bran, RM 8435 Whole Milk Powder, and RM 8436 Durum Wheat Flour) were recently distributed by NIST to 4 laboratories with expertise in food analysis for the measurement of proximates (solids, fat, protein, etc.), calories, and total dietary fiber, as appropriate. SRM 1846 Infant Formula was distributed as a quality control sample for the proximates and for analysis for individual fatty acids. Two of the materials (Whole Egg Powder and Whole Milk Powder) were distributed in an earlier interlaboratory comparison exercise in which they were analyzed for several vitamins. Value assignment of analyte concentrations in these 11 SRMs and RMs, based on analyses by the collaborating laboratories, is described in this paper. These materials are intended primarily for validation of analytical methods for the measurement of nutrients in foods of similar composition (based on AOAC INTERNATIONAL's fat–protein–carbohydrate triangle). They may also be used as “primary control materials” in the value assignment of in-house control materials of similar composition. The addition of proximate information for 10 existing reference materials means that RMs are now available from NIST with assigned values for proximates in 6 of the 9 sectors of the AOAC triangle. Five of these materials have values assigned for total dietary fiber—the first such information provided for materials available from NIST.
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6

Volegova, E. A., T. I. Maslova, V. O. Vas’kovskiy, and A. S. Volegov. "Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials." Reference materials 15, no. 1 (July 9, 2019): 21–27. http://dx.doi.org/10.20915/2077-1177-2019-15-1-21-27.

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Анотація:
Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.
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7

Lee, Sang-Soo, Seil Kim, Hee Min Yoo, Da-Hye Lee, and Young-Kyung Bae. "Development of SARS-CoV-2 packaged RNA reference material for nucleic acid testing." Analytical and Bioanalytical Chemistry 414, no. 5 (December 27, 2021): 1773–85. http://dx.doi.org/10.1007/s00216-021-03846-y.

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Анотація:
AbstractNucleic acid tests to detect the SARS-CoV-2 virus have been performed worldwide since the beginning of the COVID-19 pandemic. For the quality assessment of testing laboratories and the performance evaluation of molecular diagnosis products, reference materials (RMs) are required. In this work, we report the production of a lentiviral SARS-CoV-2 RM containing approximately 12 kilobases of its genome including common diagnostics targets such as RdRp, N, E, and S genes. The RM was measured with multiple assays using two different digital PCR platforms. To measure the homogeneity and stability of the lentiviral SARS-CoV-2 RM, reverse transcription droplet digital PCR (RT-ddPCR) was used with in-house duplex assays. The copy number concentration of each target gene in the extracted RNA solution was then converted to that of the RM solution. Their copy number values are measured to be from 1.5 × 105 to 2.0 × 105 copies/mL. The RM has a between-bottle homogeneity of 4.80–8.23% and is stable at 4 °C for 1 week and at −70 °C for 6 months. The lentiviral SARS-CoV-2 RM closely mimics real samples that undergo identical pre-analytical processes for SARS-CoV-2 molecular testing. By offering accurate reference values for the absolute copy number of viral target genes, the developed RM can be used to improve the reliability of SARS-CoV-2 molecular testing.
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8

Karachevtsev, F. N., S. G. Eroshkin, and A. N. Mosolov. "Reference material for the spectral analysis of the VSDP‑16 aluminum alloy." Measurement Standards. Reference Materials 18, no. 1 (June 13, 2022): 39–50. http://dx.doi.org/10.20915/2077-1177-2022-18-1-39-50.

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Анотація:
The control of the chemical composition of aluminum-based cathodes of the VSDP brand requires a lot of production time, as well as the availability of expensive equipment, which is not suitable for the control of the alloy composition during its smelting. The purpose of this study is to develop a technology for reference material (RM) production for spectral analysis of the VSDP-16 aluminum alloy, which meets the requirements for stability and chemical homogeneity. The RM certified values should cover the alloying range of the alloy for constructing correct calibrations in the calibration of spectrometers.The RM production technology included: melting of ingots of charge bars from the VSDP-16 alloy in a vacuum induction furnace; atomization of bars to aluminum powder; hot pressing of the resulting powder in a graphite mold on a hot pressing unit at a sintering temperature of 600C and a pressure of 20 MPa (62 kN); mechanical processing of the obtained bars. In the course of the study, the processing methods of RM melting were tested by introducing the main alloying elements and impurities. The RM homogeneity study was carried out, and it was found that the homogeneity characteristic of Sн for alloying elements is less than 1 % of the certified value, which suggests a good distribution of elements in the bulk. The study of the RM chemical composition showed that the content of elements varies and allows the RM application for calibration of spectral equipment. Calibration dependences are constructed based on optical-emission and X-ray fluorescence analyzers. Dependences are linear, which makes it possible to apply RM for calibration of spectral equipment. The developed RM is appropriate for the optical-emission method of analysis, which does not include the dissolution of samples in acids. This allows to reduce labor intensity compared to the inductively coupled plasma atomic emission method by ~3 times and energy consumption by ~3.5 times.As a result of the study, a set of certified reference materials was developed for the spectral analysis of the VSDP-16 aluminum alloy GSO 11696–2021, the certified values of which are traceable to the unit of mass fraction by direct measurements on the State Primary Standard of units of mass (molar) fraction and mass (molar) concentration of components in liquid and solid substances and materials based on spectral methods GET 196-2015.
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9

Jiang, Zhi Hua, Xiao Dong Yang, Dong Mei Tang, and Zhi Ming Wang. "Study & Manufacture RM of Industrial CT System." Applied Mechanics and Materials 347-350 (August 2013): 80–84. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.80.

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Анотація:
This paper introduces a method of studied and manufactured reference material for calibrating magnification of computed tomography system. The measurement procedure and certified value method of the reference material were also described. Moreover, uncertainty of measurement was evaluated in this paper, by which a state level of confidence was accompanied. Finally one example of application of the reference material was described. We thought that reference material of CT system will update its function and develop its applied field.
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10

Krylov, A. I., A. Y. Mikheeva, A. G. Budko, and I. Yu Tkachenko. "Metrological support of phthalate content measurements: reference material for the composition of a solution of six priority phthalates in methanol." Measurement Standards. Reference Materials 17, no. 3 (October 13, 2021): 5–19. http://dx.doi.org/10.20915/2687-0886-2021-17-3-5-19.

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Анотація:
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.
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11

Van Egmond, Hans P., and Peter J. Wagstaffe. "Development of Milk Powder Reference Materials Certified for Aflatoxin Mt Content (Part II): Certification of Milk Powder RM 283." Journal of AOAC INTERNATIONAL 71, no. 6 (November 1, 1988): 1180–82. http://dx.doi.org/10.1093/jaoac/71.6.1180.

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Анотація:
Abstract The development of a full cream milk powder reference material, certified for its aflatoxin M, content (target concentration: 0.1 fig/ kg), is described. The material (RM 283) was prepared and certified within the Reference Material Programme of the Community Bureau of Reference, along with other members of a series of milk powder reference materials. Homogeneity, evaluated by determining the aflatoxin M, content of 30 units, was found to be acceptable (coefficient of variation of analysis results: 9.1%); stability has been demonstrated in a long-term study. The certification exercise involved 7 laboratories. Calibration, control of recoveries, blank values, and independence of the replicate measurements were emphasized. All sets of results of the certification exercise were accepted for statistical evaluation. A certified value for the aflatoxin M, content: 0.09(+0.04)(-0.02) Mg/kg was derived. The certification of RM 283 completes the series of 4 milk powder reference materials having certified aflatoxin M, contents
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12

Ihnat, Milan. "Development of a New Series of Agricultural/Food Reference Materials for Analytical Quality Control of Elemental Determinations." Journal of AOAC INTERNATIONAL 77, no. 6 (November 1, 1994): 1605–26. http://dx.doi.org/10.1093/jaoac/77.6.1605.

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Анотація:
Abstract Ten new Agricultural/Food Reference Materials — Bovine Muscle Powder (National Institute of Standards and Technology [NIST], code NIST RM 8414), Whole Egg Powder (NIST RM 8415), Microcrystalline Cellulose (NIST RM 8416), Wheat Gluten (NIST RM 8418), Corn Starch (NIST RM 8432), Corn Bran (NIST RM 8433), Whole Milk Powder (NIST RM 8435), Durum Wheat Flour (NIST RM 8436), Hard Red Spring Wheat Flour (NIST RM 8437) and Soft Winter Wheat Flour (NIST RM 8438) — were prepared by application of milling, irradiation, sieving, blending, and packaging procedures. Excellent material homogeneity was found for virtually all major, minor, and trace elements of interest. The reference materials were characterized with respect to elemental composition via an extensive international, interlaboratory characterization (certification) campaign. Chemical analyses conducted in 73 cooperating laboratories applying 13 major classes of independently different analytical methods led to 278 concentration values for 34 nutritionally, toxicologically, and environmentally pertinent elements. A total of 213 best-estimate and 65 informational concentration values are available for Al, As, B, Ba, Br, Ca, Cd, CI, Co, Cr, Cs, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, N, Na, Ni, P, Pb, Rb, S, Sb, Se, Sr, Ti, V, W, and Zn. These products make a substantial contribution to the existing world repertoire of biological reference materials with respect to natural matrix and elemental composition. They are expected to be useful to analysts for quality control of analytical data. Applications include evaluations of analytical methods and instruments used in nutritional, toxicological, monitory, regulatory, environmental, agricultural, and other investigations. These products are available to the analytical community from the Standard Reference Materials Program, NIST, Gaithersburg, MD.
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13

STYARINI, Dyah, and Jarnuzi GUNLAZUARDI. "FEASIBILITY STUDY ON THE DEVELOPMENT OF REFERENCE MATERIAL OF PESTICIDE IN BLACK TEA." Periódico Tchê Química 14, no. 27 (January 20, 2017): 146–54. http://dx.doi.org/10.52571/ptq.v14.n27.2017.146_periodico27_pgs_146_154.pdf.

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Анотація:
In this paper, a study on development of reference material (RM) for α-endosulfan and bifenthrin in black tea as a matrix is reported. The study was conducted on the basis that such RMs was presently not available in Indonesia. To obtain a good and proper RM, a feasibility study of RM development is extremely required. The RM was firstly prepared by grinding the tea leaf to have particle size of about 150-106 μm and water content of about 5.99%. A small portion of the grinded tea leaf was then spiked with hexane solution containing both target analytes at certain concentrations, followed by a proper drying to obtain initial candidate of RM (iCRM). The iCRM was then well-mixed properly with another portion of non-spiked grinded tea material to get final candidate reference material (fCRM) powder. A gas chromatography equipped with electron capture detector was used for analyte identification and the feasibility of the method was evaluated in term of spiking technique and homogenization process. The evaluation by ANOVA showed that fCRM was statistically considered to be homogeneous and having α-endosulfan and bifentrin mass fraction ± U of 380.32 (±120.32) ng.g-1 and 522.74 (±148.65) ng.g-1 in dry weight basis, respectively.
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14

Migal, P. V., S. V. Medvedevskikh, and V. A. Firsanov. "A method for estimating the certified value uncertainty of a multicomponent reference material." Reference materials 15, no. 1 (July 9, 2019): 5–13. http://dx.doi.org/10.20915/2077-1177-2019-15-1-5-13.

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Анотація:
This paper presents the results of a series of studies aimed at investigating the reference material (RM) of a multicomponent solution. An algorithm for estimating the uncertainty induced by the chemical element content in the RM is proposed taking into account the mass of the measurand in each component of the mixture. The results calculated according to the preparation procedure using the proposed algorithm were confirmed by the Monte Carlo method, while the elemental content in the mixture was confirmed via inductively coupled plasma optical emission spectroscopy. The applicability of weighted mean estimates for characterizing an RM of a multicomponent solution is shown.
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15

Alvisi, Marco, Markus Blome, Michael Griepentrog, Vasile-Dan Hodoroaba, Peter Karduck, Marco Mostert, Michele Nacucchi, et al. "The Determination of the Efficiency of Energy Dispersive X-Ray Spectrometers by a New Reference Material." Microscopy and Microanalysis 12, no. 5 (September 19, 2006): 406–15. http://dx.doi.org/10.1017/s1431927606060557.

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Анотація:
A calibration procedure for the detection efficiency of energy dispersive X-ray spectrometers (EDS) used in combination with scanning electron microscopy (SEM) for standardless electron probe microanalysis (EPMA) is presented. The procedure is based on the comparison of X-ray spectra from a reference material (RM) measured with the EDS to be calibrated and a reference EDS. The RM is certified by the line intensities in the X-ray spectrum recorded with a reference EDS and by its composition. The calibration of the reference EDS is performed using synchrotron radiation at the radiometry laboratory of the Physikalisch-Technische Bundesanstalt. Measurement of RM spectra and comparison of the specified line intensities enables a rapid efficiency calibration on most SEMs. The article reports on studies to prepare such a RM and on EDS calibration and proposes a methodology that could be implemented in current spectrometer software to enable the calibration with a minimum of operator assistance.
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16

Postek, M. T., A. E. Vladar, N. F. Zhang, and R. Larrabee. "New Scanning Electron Microscope Sharpness Standard: NIST Reference Material 8091 (Rm 8091)." Microscopy and Microanalysis 7, S2 (August 2001): 494–95. http://dx.doi.org/10.1017/s1431927600028543.

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Анотація:
All scanning electron microscopes, whether they are in laboratory or on the production line, slowly lose performance as the instrument is used. This loss of performance is due to a whole array of contributing factors including misalignments, contamination and increases in source diameter. Identifying a loss in “sharpness” easily recognizes this performance decrease. Reference Material 8091 (RM 8091) is intended primarily for use in routinely checking the sharpness performance of scanning electron microscopes (Fig. 1). RM 8091 is designed to be used in conjunction with the SPECTEL SEM Monitor Program, the NIST Kurtosis program,3 or the University of Tennessee SMART program. RM 8091 is supplied as a small, approximately 2 mm x 2 mm diced semiconductor chip. This sample is capable of being mounted directly on to a wafer, wafer piece or specimen stub for insertion into a laboratory scanning electron microscope or wafer inspection scanning electron microscope.
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17

Medvedevskikh, M. Y., N. L. Vostrikova, A. S. Sergeeva, and V. V. Studenok. "Application of the lyophilization system for preparation of reference materials for composition of nutrition products." Measurement Standards. Reference Materials 17, no. 1 (May 8, 2021): 35–45. http://dx.doi.org/10.20915/2687-0886-2021-17-1-35-45.

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Анотація:
The article presents the application of the lyophilization system for preparation of reference materials (RM) for composition of nutritive products samples. The purpose of the research was the development of lyophilization procedure of RM for composition of poultry meat samples preparation with certified values of mass fraction of moisture, nitrogen (protein) and fat.The poultry meat of two types was used as the primary material for RM for poultry meat composition preparation -1) white meat (chicken breast); 2) red meat (chicken thigh). The procedure included pounding, boiling, freezing and lyophilisation (syn. freeze drying). The researches for homogeneity were implemented with hot air dryer standard system from the State primary standard GET 173-2017. Measurement of nitrogen (protein) mass fraction was performed on State secondary standard GVET176-1-2010. Measurements of fat mass fraction were performed with accordance to State Primary Reference Measurement Procedure.The total time of lyophilization process for samples № 1 and № 2 was 19 and 28 hours, respectively. The total mass loss for sample № 1 was about 63 %, for sample № 2 was about 65 %. The difference in material moisture mass fraction values of materials dried on different trays of freeze dryer was statistically significant, i. e., material was non-homogeneous. To obtain a homogeneous material, an additional homogenization procedure was performed: grinding in a laboratory mill, sieving through a sieve, thorough mixing and conditioning. The certified values of moisture, nitrogen, protein, fat mass fraction for the sample № 1 were accordingly 4,5 %, 14,74 %, 92,1 %, 7,9 %. The same values in the same sequence were 6,3 %, 12,21 %, 76,3 %, 23,8 %.The procedure of lyophilisation was developed for production of reference materials for composition of boiled and freeze-dried poultry meat. The usage of this lyophilisation system allowed to ensure a RM expiration date of six months at ambient temperature of (7±3) °C and relative humidity no more than 60 %. The Reference Materials for composition of boiled and freeze-dried poultry meat was added into Register of certified RMs under № GSO 11276-2019 by the results.
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18

Budd, Jeffrey R., Cas Weykamp, Robert Rej, Finlay MacKenzie, Ferruccio Ceriotti, Neil Greenberg, Johanna E. Camara, et al. "IFCC Working Group Recommendations for Assessing Commutability Part 3: Using the Calibration Effectiveness of a Reference Material." Clinical Chemistry 64, no. 3 (March 1, 2018): 465–74. http://dx.doi.org/10.1373/clinchem.2017.277558.

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Анотація:
Abstract A process is described to assess the commutability of a reference material (RM) intended for use as a calibrator based on its ability to fulfill its intended use in a calibration traceability scheme to produce equivalent clinical sample (CS) results among different measurement procedures (MPs) for the same measurand. Three sources of systematic error are elucidated in the context of creating the calibration model for translating MP signals to measurand amounts: calibration fit, calibrator level trueness, and commutability. An example set of 40 CS results from 7 MPs is used to illustrate estimation of bias and variability for each MP. The candidate RM is then used to recalibrate each MP, and its effectiveness in reducing the systematic error among the MPs within an acceptable level of equivalence based on medical requirements confirms its commutability for those MPs. The RM is declared noncommutable for MPs for which, after recalibration, the CS results do not agree with those from other MPs. When a lack of agreement is found, other potential causes, including lack of calibration fit, should be investigated before concluding the RM is noncommutable. The RM is considered fit for purpose for those MPs where commutability is demonstrated.
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19

Nguyen, H. G. T., C. M. Sims, B. Toman, J. Horn, R. D. van Zee, M. Thommes, R. Ahmad, et al. "A reference high-pressure CH4 adsorption isotherm for zeolite Y: results of an interlaboratory study." Adsorption 26, no. 8 (September 11, 2020): 1253–66. http://dx.doi.org/10.1007/s10450-020-00253-0.

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Abstract This paper reports the results of an international interlaboratory study led by the National Institute of Standards and Technology (NIST) on the measurement of high-pressure surface excess methane adsorption isotherms on NIST Reference Material RM 8850 (Zeolite Y), at 25 °C up to 7.5 MPa. Twenty laboratories participated in the study and contributed over one-hundred adsorption isotherms of methane on Zeolite Y. From these data, an empirical reference equation was determined, along with a 95% uncertainty interval (Uk=2). By requiring participants to replicate a high-pressure reference isotherm for carbon dioxide adsorption on NIST Reference Material RM 8852 (ZSM-5), this interlaboratory study also demonstrated the usefulness of reference isotherms in evaluating the performance of high-pressure adsorption experiments.
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20

Nguyen Thi, Hang, Phuong Thao Le Thi, Huu Cuong Dang, Huyen Trang Luu Thi, and Hong Hao Le Thi. "Study on the production of Reference Material (RM) for Vitamin B1, B2, B6 in health supplements." Heavy metals and arsenic concentrations in water, agricultural soil, and rice in Ngan Son district, Bac Kan province, Vietnam 4, no. 4 (December 27, 2021): 307–14. http://dx.doi.org/10.47866/2615-9252/vjfc.3853.

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Анотація:
Vitamins are essential nutrients commonly found in food products in general and health supplements in particular. In order to accurately evaluate product quality, laboratories need to use reference material in analysis, proficiency assessment, method validation and ensure the validity of the results. The use of reference materials plays an important role in the quality control of test results and is a mandatory requirement for laboratories wishing to demonstrate appropriate competence as required by ISO/IEC 17025:2017. The need to provide reference materials for laboratories is huge. However, at present, there are very few domestic organizations that can produce reference materials, while the cost of buying reference materials from reputable firms in the world is expensive. In this study, we introduced the procedure and production reference materials for the analysis of B-group vitamins (B1, B2, B6). These reference materials were evaluated for homogeneity and stability in 322 days. The certified values are consistent with the concentrations of substances present in normal samples in practice. The measurement uncertainty ranges from 14.5 - 23.3 %. The reference materials can be used for internal quality control for domestic laboratories and is also a premise for further research on standard samples with different matrix and analytical criteria.
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21

Sergeeva, A. S., N. L. Vostrikova, and M. Yu Medvedevskikh. "Development of food industry metrological assurance complex." Measurement Standards. Reference Materials 17, no. 1 (May 8, 2021): 21–33. http://dx.doi.org/10.20915/2687-0886-2021-17-1-21-33.

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Анотація:
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.
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22

Vladár, AE, and MT Postek. "Reference Material (RM) 8820: A New Scanning Electron Microscope Scale Calibration Artifact." Microscopy and Microanalysis 15, S2 (July 2009): 668–69. http://dx.doi.org/10.1017/s1431927609097943.

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23

Ma, Li, John Song, Eric Whitenton, Alan Zheng, Theodore Vorburger, and Jack Zhou. "NIST Bullet Signature Measurement System for RM (Reference Material) 8240 Standard Bullets." Journal of Forensic Sciences 49, no. 4 (2004): 1–11. http://dx.doi.org/10.1520/jfs2003384.

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24

Nilsson, Göran, Jeffrey R. Budd, Neil Greenberg, Vincent Delatour, Robert Rej, Mauro Panteghini, Ferruccio Ceriotti, et al. "IFCC Working Group Recommendations for Assessing Commutability Part 2: Using the Difference in Bias between a Reference Material and Clinical Samples." Clinical Chemistry 64, no. 3 (March 1, 2018): 455–64. http://dx.doi.org/10.1373/clinchem.2017.277541.

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Анотація:
Abstract A process is described to assess the commutability of a reference material (RM) intended for use as a calibrator, trueness control, or external quality assessment sample based on the difference in bias between an RM and clinical samples (CSs) measured using 2 different measurement procedures (MPs). This difference in bias is compared with a criterion based on a medically relevant difference between an RM and CS results to make a conclusion regarding commutability. When more than 2 MPs are included, the commutability is assessed pairwise for all combinations of 2 MPs. This approach allows the same criterion to be used for all combinations of MPs included in the assessment. The assessment is based on an error model that allows estimation of various random and systematic sources of error, including those from sample-specific effects of interfering substances. An advantage of this approach is that the difference in bias between an RM and the average bias of CSs at the concentration (i.e., amount of substance present or quantity value) of the RM is determined and its uncertainty estimated. An RM is considered fit for purpose for those MPs for which commutability is demonstrated.
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Andrade, Daniel Fernandes, Raquel Cardoso Machado, Márcio Arruda Bacchi, and Edenir Rodrigues Pereira-Filho. "Proposition of electronic waste as a reference material – part 1: sample preparation, characterization and chemometric evaluation." Journal of Analytical Atomic Spectrometry 34, no. 12 (2019): 2394–401. http://dx.doi.org/10.1039/c9ja00283a.

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26

Schaffer, R., G. N. Bowers, and R. S. Melville. "History of NIST's contributions to development of standard reference materials and reference and definitive methods for clinical chemistry." Clinical Chemistry 41, no. 9 (September 1, 1995): 1306–12. http://dx.doi.org/10.1093/clinchem/41.9.1306.

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Abstract The issuance of cholesterol as a Standard Reference Material (SRM) in 1967 started the National Institute of Standards and Technology (NIST; then named the National Bureau of Standards) on a major effort to help clinical laboratories establish and improve the quality of measurements they make. NIST now issues three kinds of SRMs for that purpose: analyte samples of certified purity as primary standards, serum samples having certified analyte concentrations as accuracy controls, and materials certified for calibrating instruments. In working with clinical laboratory scientists to establish Reference Methods (RMs) for measuring the analytes, NIST developed Definitive Methods (DMs) to use for evaluating RM accuracy and then used the DMs for assigning analyte values to its SRMs. The development of SRMs and DMs is discussed.
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27

Diepeveen, Laura E., Coby M. M. Laarakkers, Gustavo Martos, Marta E. Pawlak, Fatih F. Uğuz, Kim E. S. A. Verberne, Rachel P. L. van Swelm, et al. "Provisional standardization of hepcidin assays: creating a traceability chain with a primary reference material, candidate reference method and a commutable secondary reference material." Clinical Chemistry and Laboratory Medicine (CCLM) 57, no. 6 (May 27, 2019): 864–72. http://dx.doi.org/10.1515/cclm-2018-0783.

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Abstract Background Hepcidin concentrations measured by various methods differ considerably, complicating interpretation. Here, a previously identified plasma-based candidate secondary reference material (csRM) was modified into a serum-based two-leveled sRM. We validated its functionality to increase the equivalence between methods for international standardization. Methods We applied technical procedures developed by the International Consortium for Harmonization of Clinical Laboratory Results. The sRM, consisting of lyophilized serum with cryolyoprotectant, appeared commutable among nine different measurement procedures using 16 native human serum samples in a first round robin (RR1). Harmonization potential of the sRM was simulated in RR1 and evaluated in practice in RR2 among 11 measurement procedures using three native human plasma samples. Comprehensive purity analysis of a candidate primary RM (cpRM) was performed by state of the art procedures. The sRM was value assigned with an isotope dilution mass spectrometry-based candidate reference method calibrated using the certified pRM. Results The inter-assay CV without harmonization was 42.1% and 52.8% in RR1 and RR2, respectively. In RR1, simulation of harmonization with sRM resulted in an inter-assay CV of 11.0%, whereas in RR2 calibration with the material resulted in an inter-assay CV of 19.1%. Both the sRM and pRM passed international homogeneity criteria and showed long-term stability. We assigned values to the low (0.95±0.11 nmol/L) and middle concentration (3.75±0.17 nmol/L) calibrators of the sRM. Conclusions Standardization of hepcidin is possible with our sRM, which value is assigned by a pRM. We propose the implementation of this material as an international calibrator for hepcidin.
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Kim, Seung-Hwan, Byungjoo Kim, Kwangguk Joo, Su-Eon Ji, Dae-Won Chung, and Seok-Ki Lee. "Mass Balance Method for Purity Assessment for Pesticide Analytical Standards." Journal of Environmental Analysis, Health and Toxicology 24, no. 3 (September 30, 2021): 127–32. http://dx.doi.org/10.36278/jeaht.24.3.127.

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Imazamox, a widely used herbicide, is currently managed by the Pesticide MRLs and Positive List System of the Ministry of Food and Drug Safety, and the development of reliable standard materials for analysis is urgently required. To confirm the reliability of the mass balance method, we measured the purity of the imazamox reference material (RM) certified by an RM producer accredited with ISO Guide 34 and estimated measurement uncertainty. According to this method, the content of structurally similar organic impurities was measured using high-performance liquid chromatographic coupled with ultraviolet (HPLC-UV), and the moisture, volatile impurities, and non-volatile impurities were quantitatively analyzed using a thermogravimetric analyzer (TGA). Purity and measurement uncertainty were calculated based on analysis of the HPLC-UV and TGA results obtained, and the validity of these values was confirmed by comparing with the values provided in the RM certificate.
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29

Blais, Jonatan, Sylvie Giroux, André Caron, Valérie Clément, and François Rousseau. "Development of Reference Materials for Noninvasive Prenatal Aneuploidy Testing by Massively Parallel Sequencing: A Proof-of-Concept Study." Journal of Applied Laboratory Medicine 4, no. 1 (July 1, 2019): 50–60. http://dx.doi.org/10.1373/jalm.2018.028100.

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Abstract Background Noninvasive prenatal aneuploidy testing (NIPT) represents the first large-scale clinical application of massively parallel sequencing technology. However, no NIPT reference material (RM) has yet been widely adopted, impeding the development of quality management systems and standardization. Developing an NIPT RM from a biological sample is complicated by the low concentration of cell-free DNA (cfDNA), which implies pooling specimens and frequent resampling. Methods We tested the feasibility of using DNA from immortalized cell lines of a woman and her aneuploid offspring to spike an artificial plasma matrix. Enzymatic fragmentation of extracted DNA was optimized to achieve fragment size profiles with a mode of 150 to 200 bp, similar to biological cfDNA. This synthetic material was compared with routine biological samples from pregnant women by a targeted NIPT assay in a multiplex sequencing run on a Proton platform. Results Sequencing statistics were similar between artificially prepared material and routine biological samples, as well as relative chromosomal representation, and no matrix effects could be detected. Estimate of fetal fraction (FF) was within the range of expected value, and aneuploidy detection statistic (z-score) was also comparable between both types of samples. Conclusions Artificial plasma spiked with DNA from cell lines of mother and offspring is a promising strategy for developing NIPT RM. This type of material would offer the advantage of a constant and stable composition, allowing for greater standardization of NIPT assays. Moreover, it preserves the parental relatedness used by targeted assay to estimate FF by identification of paternal alleles in single-nucleotide polymorphisms or other variable regions.
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30

He, Hua-Jun, Biswajit Das, Megan H. Cleveland, Li Chen, Corinne E. Camalier, Liang-Chun Liu, Kara L. Norman, et al. "Development and interlaboratory evaluation of a NIST Reference Material RM 8366 for EGFR and MET gene copy number measurements." Clinical Chemistry and Laboratory Medicine (CCLM) 57, no. 8 (July 26, 2019): 1142–52. http://dx.doi.org/10.1515/cclm-2018-1306.

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Abstract Background The National Institute of Standards and Technology (NIST) Reference Material RM 8366 was developed to improve the quality of gene copy measurements of EGFR (epidermal growth factor receptor) and MET (proto-oncogene, receptor tyrosine kinase), important targets for cancer diagnostics and treatment. The reference material is composed of genomic DNA prepared from six human cancer cell lines with different levels of amplification of the target genes. Methods The reference values for the ratios of the EGFR and MET gene copy numbers to the copy numbers of reference genes were measured using digital PCR. The digital PCR measurements were confirmed by two additional laboratories. The samples were also characterized using Next Generation Sequencing (NGS) methods including whole genome sequencing (WGS) at three levels of coverage (approximately 1 ×, 5 × and greater than 30 ×), whole exome sequencing (WES), and two different pan-cancer gene panels. The WES data were analyzed using three different bioinformatic algorithms. Results The certified values (digital PCR) for EGFR and MET were in good agreement (within 20%) with the values obtained from the different NGS methods and algorithms for five of the six components; one component had lower NGS values. Conclusions This study shows that NIST RM 8366 is a valuable reference material to evaluate the performance of assays that assess EGFR and MET gene copy number measurements.
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Miller, W. Greg, Heinz Schimmel, Robert Rej, Neil Greenberg, Ferruccio Ceriotti, Chris Burns, Jeffrey R. Budd, et al. "IFCC Working Group Recommendations for Assessing Commutability Part 1: General Experimental Design." Clinical Chemistry 64, no. 3 (March 1, 2018): 447–54. http://dx.doi.org/10.1373/clinchem.2017.277525.

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Abstract Commutability is a property of a reference material (RM) that relates to the closeness of agreement between results for an RM and results for clinical samples (CSs) when measured by ≥2 measurement procedures (MPs). Commutability of RMs used in a calibration traceability scheme is an essential property for them to be fit for purpose. Similarly, commutability of trueness controls or external quality assessment samples is essential when those materials are used to assess trueness of results for CSs. This report is part 1 of a 3-part series describing how to assess commutability of RMs. Part 1 defines commutability and addresses critical components of the experimental design for commutability assessment, including selection of individual CSs, use of pooled CSs, qualification of MPs for inclusion, establishing criteria for the determination that an RM is commutable, generalization of commutability conclusions to future measurements made with the MPs included in the assessment, and information regarding commutability to be included in the certificate for an RM. Parts 2 and 3 in the series present 2 different statistical approaches to commutability assessment that use fixed criteria related to the medical decisions that will be made using the laboratory test results.
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Serrano-Munoz, Itziar, Vincent Magnier, Florent Brunel, and Philippe Dufrenoy. "Influence of the Composition on the Compressive Behaviour of a Semi-Metallic Brake-Pad Material." Materials 15, no. 22 (November 9, 2022): 7911. http://dx.doi.org/10.3390/ma15227911.

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Анотація:
The contact interface between the rotation and static part of a friction brake is central to the optimal functioning of the brake system due to the occurrence of heat dissipation, mechanical interaction and thermal exchanges. Generally, braking performances are evaluated by the energetic efficiency and wear rates of the contact surface. However, the compressive behaviour of the contact materials has also a significant contribution to the overall performances. In this work, the meso- and microscopic compressive behaviour of a sintered semi-metallic brake-pad material is investigated mainly via compression testing coupled with Digital Image Correlation (DIC) technique, as well as optical and scanning electron microscopy (SEM) analysis. The composition of a reference material (RM) is simplified to a selection of nine components, as opposed to up to thirty components typically used in commercial brake-pad materials. The retained components are considered as the most crucial for safe-operating performances. At the studied stress levels, the RM material is flexible (E = 5330 MPa), deformable (Ezz-plastic = −0.21%), and exhibits hysteresis loops. Subsequently, the contribution to the mechanical response of each individual component is investigated by producing the so-called dissociated materials, where the number of components is, at a time, further reduced. It is observed that the macroscopic behaviour is mainly controlled by the content (i.e., size distribution, shape and nature) of graphite particles, and that the hysteresis is only related to one of the two types of graphite used (G2 particles). Moreover, RM containing 13 wt% of G2 particles embedded in a relatively soft matrix (10.86 GPa) is able to increase the hysteresis (by 35%) when compared to the dissociated material containing 20 wt% of G2 particles which is embedded in a stiffer matrix (E = 106 GPa).
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33

Braga, Federica, and Mauro Panteghini. "Commutability of reference and control materials: an essential factor for assuring the quality of measurements in Laboratory Medicine." Clinical Chemistry and Laboratory Medicine (CCLM) 57, no. 7 (June 26, 2019): 967–73. http://dx.doi.org/10.1515/cclm-2019-0154.

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Abstract Traceability to a common reference ensures equivalence of results obtained by different assays. Traceability is achieved by an unbroken sequence of calibrations, using reference materials (RMs) that must be commutable. Using non-commutable RMs for calibration will introduce a bias in the calibrated method producing incorrect results for clinical samples (CS). Commutability was defined in 1973 as “the ability of an enzyme material to show inter-assay activity changes comparable to those of the same enzyme in human serum” and later extended as a characteristic of all RMs. However, the concept is still poorly understood and appreciated. Commutability assessment has been covered in CLSI guidelines and requires: (a) selection of 20 CS spanning the relevant concentration range; (b) analysis of both RM and CS with the pair of procedures; (c) data elaboration using regression analysis and calculation if RM fall within the 95% prediction interval defined by CS. This approach has been criticized and to improve it The International Federation of Clinical Chemistry and Laboratory Medicine established a working group that recently finalized recommendations. Commutability is also a requirement for the applicability of external quality assessment (EQA) results in the evaluation of the performance of participating laboratories in terms of standardization of their measurements. Unfortunately, EQA materials are usually not validated for commutability.
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34

Pedersen, Nanna Bjerregaard, Notburga Gierlinger, and Lisbeth Garbrecht Thygesen. "Bacterial and abiotic decay in waterlogged archaeological Picea abies (L.) Karst studied by confocal Raman imaging and ATR-FTIR spectroscopy." Holzforschung 69, no. 1 (January 1, 2015): 103–12. http://dx.doi.org/10.1515/hf-2014-0024.

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Abstract Waterlogged archaeological Norway spruce [Picea abies (L.) Karst] poles were studied by means of confocal Raman imaging (CRI) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) analysis to determine lignin and polysaccharide composition and distribution in the cell wall. The waterlogged archaeological wood (WAW) was submerged under anoxic conditions for approximately 400 years and solely decayed by erosion bacteria (EB). CRI showed that decayed tracheids contain a residual material (RM) with heterogeneous lignin distribution; within the same tracheid RM often contained regions with intensities lower than sound S2 layers up to intensity values as high as the compound middle lamella (CML). CRI revealed strong depletion of carbohydrates in RM which indicated that EB are able to utilise the carbohydrate fraction of the cell wall effectively. Raman bands assigned to lignin did not show any difference between RM and sound S2. This is a hint that EB do not modify the lignin structure. Sound WAW free from EB decay showed evidence of loss of acetyl groups in glucomannan, loss of un-conjugated ester linkages in the lignin-carbohydrate complexes between xylan and lignin, and minor oxidation of the lignin polymer compared to recent reference material. This is evidence for abiotic decay in the course of waterlogging.
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35

Ramprakash, Jayanthi, Matthew G. Butler, Russell K. Garlick, and Yves Konigshofer. "Abstract 3376: Novel reference materials for the analysis of methylation in liquid biopsies." Cancer Research 82, no. 12_Supplement (June 15, 2022): 3376. http://dx.doi.org/10.1158/1538-7445.am2022-3376.

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Анотація:
Abstract Here we describe new reference materials (RMs) for liquid biopsies that are designed to mimic the methylation found in circulating cell-free DNA (ccfDNA). Methylation is an important epigenetic modification that influences cellular differentiation and gene expression. Recently, liquid biopsies have started to incorporate analyses of epigenetic modifications for screening purposes to detect cancer-derived DNA in the blood. Additionally, epigenetic modifications are being used to also assign a tissue of origin to the cancer to direct confirmatory diagnostic procedures. Obtaining sufficient amounts of ccfDNA for assay development, validation, and proficiency testing is difficult. Furthermore, methods of analyzing the epigenetic modifications, such as bisulfite conversion, can damage a significant fraction of the input material; but, failing to carry them out to completion can result in an over-estimation of methylation. To address the challenges associated with assessing the methylation of ccfDNA, we created and characterized three types of RMs. The first type of RM is a fragmented genome of the GM24385 reference cell line that is used to create a set of RMs with different degrees of methylation (0%, ~25%, ~50%, ~75% and close to 100%). The exact degree of methylation was assigned by digital PCR using assays for heterozygous SNPs, where one allele is both a site for CpG methylation and a recognition site for a methylation-sensitive restriction enzyme while the other allele is not. The second type of RM is an amplified ccfDNA sample that has been methylated similarly but also reproduces the fragment lengths and genomic representation biases of ccfDNA. The degree of methylation was assigned by digital PCR, but only a subset of assays was useful because not all SNPs were heterozygous. The third type of RM is an amplified ccfDNA sample that has been processed to mimic the methylation found in the original ccfDNA. Analyses of the RMs by whole genome sequencing (WGS) showed that, while bisulfite conversion and/or the amplification of the resulting dU-containing DNA appeared to lead to significant biases in genomic representation, the resulting data was generally in agreement with the amount of methylation assigned by digital PCR. Additionally, it was possible to prepare an RM that generally reproduces the methylation found in ccfDNA; although, this was limited to individual molecules having either no or close to full methylation, which is unlikely to be the case for all molecules of ccfDNA in vivo. Citation Format: Jayanthi Ramprakash, Matthew G. Butler, Russell K. Garlick, Yves Konigshofer. Novel reference materials for the analysis of methylation in liquid biopsies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3376.
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36

Szidat, S., G. Bench, V. Bernardoni, G. Calzolai, C. I. Czimczik, L. Derendorp, U. Dusek, et al. "Intercomparison of 14C Analysis of Carbonaceous Aerosols: Exercise 2009." Radiocarbon 55, no. 3 (2013): 1496–509. http://dx.doi.org/10.1017/s0033822200048426.

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Анотація:
Radiocarbon analysis of the carbonaceous aerosol allows an apportionment of fossil and non-fossil sources of airborne particulate matter (PM). A chemical separation of total carbon (TC) into its subtractions organic carbon (OC) and elemental carbon (EC) refines this powerful technique, as OC and EC originate from different sources and undergo different processes in the atmosphere. Although 14C analysis of TC, EC, and OC has recently gained increasing attention, interlaboratory quality assurance measures have largely been missing, especially for the isolation of EC and OC. In this work, we present results from an intercomparison of 9 laboratories for 14C analysis of carbonaceous aerosol samples on quartz fiber filters. Two ambient PM samples and 1 reference material (RM 8785) were provided with representative filter blanks. All laboratories performed 14C determinations of TC and a subset of isolated EC and OC for isotopic measurement. In general, 14C measurements of TC and OC agreed acceptably well between the laboratories, i.e. for TC within 0.015–0.025 F14C for the ambient filters and within 0.041 F14C for RM 8785. Due to inhomogeneous filter loading, RM 8785 demonstrated only limited applicability as a reference material for 14C analysis of carbonaceous aerosols. 14C analysis of EC revealed a large deviation between the laboratories of 28–79% as a consequence of different separation techniques. This result indicates a need for further discussion on optimal methods of EC isolation for 14C analysis and a second stage of this intercomparison.
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37

Chugunova, M. M., N. Yu Gryazskikh, I. N. Zyablikova, A. V. Ivanov, and A. N. Shobina. "Luminescence measurements: reference materials for composition of sodium adenosine triphosphate aqueous solution." Measurement Standards. Reference Materials 17, no. 3 (October 13, 2021): 35–44. http://dx.doi.org/10.20915/2687-0886-2021-17-3-35-44.

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Анотація:
The authors evaluated the possibility of using the luminometry method which allows checking the level of sanitation and hygiene in industries and is one of the most effective methods of «rapid microbiology». Such key stages of development of reference material for sodium adenosine triphosphate with the certified values as analysis of similar reference materials, selection of source material of the reference material, conducting experimental studies, and establishing the metrological characteristics of reference material with traceability to state primary measurement standard were provided in the paper. Considering that the selective optical density at the characteristic wavelength is directly proportional to the concentration of the absorbing component (sodium adenosine triphosphate), the stability of R M was studied by spectrophotometry. The stability of the RM material to assess the uncertainty of the measurement results was carried out by the isochronous method. The result of the study is the possibility of ensuring the traceability of measurement results based on luminescence to primary measurement standard by sodium adenosine triphosphate concentration. In addition to the above, the authors selected the optimal value of that concentration and established metrological properties for GSO 11606-2020 R M for the composition of sodium adenosine triphosphate aqueous solution (mass concentration: from 0,09 to 0,11 g/dm3; extended uncertainty: 0,015 g/dm3). Usage of this CRM in performing tests, calibrations, and verification of measuring instruments allows providing the unbiased assessment of the measuring capabilities of luminescent measuring instruments, including in terms of determining the error of the measurements carried out.
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38

Marinenko, Ryna B., Shirley Turner, David S. Simons, Savelas A. Rabb, Rolf L. Zeisler, Lee L. Yu, Dale E. Newbury, et al. "Characterization of SiGe Films for Use as a National Institute of Standards and Technology Microanalysis Reference Material (RM 8905)." Microscopy and Microanalysis 16, no. 1 (December 24, 2009): 1–12. http://dx.doi.org/10.1017/s1431927609991231.

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Анотація:
AbstractBulk silicon-germanium (SiGe) alloys and two SiGe thick films (4 and 5 μm) on Si wafers were tested with the electron probe microanalyzer (EPMA) using wavelength dispersive spectrometers (WDS) for heterogeneity and composition for use as reference materials needed by the microelectronics industry. One alloy with a nominal composition of Si0.86Ge0.14 and the two thick films with nominal compositions of Si0.90Ge0.10 and Si0.75Ge0.25 on Si, evaluated for micro- and macroheterogeneity, will make good microanalysis reference materials with an overall expanded heterogeneity uncertainty of 1.1% relative or less for Ge. The bulk Ge composition in the Si0.86Ge0.14 alloy was determined to be 30.228% mass fraction Ge with an expanded uncertainty of the mean of 0.195% mass fraction. The thick films were quantified with WDS-EPMA using both the Si0.86Ge0.14 alloy and element wafers as reference materials. The Ge concentration was determined to be 22.80% mass fraction with an expanded uncertainty of the mean of 0.12% mass fraction for the Si0.90Ge0.10 wafer and 43.66% mass fraction for the Si0.75Ge0.25 wafer with an expanded uncertainty of the mean of 0.25% mass fraction. The two thick SiGe films will be issued as National Institute of Standards and Technology Reference Materials (RM 8905).
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39

Henderson, L. O., W. H. Hannon, S. J. Smith, and G. R. Cooper. "An international collaborative study on standardization of apolipoproteins A-I and B. Part II. Evaluation of contributions of antisera to among-laboratory variance components." Clinical Chemistry 33, no. 12 (December 1, 1987): 2250–56. http://dx.doi.org/10.1093/clinchem/33.12.2250.

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Анотація:
Abstract Local antisera (LA) were compared with a common interim reference antiserum (IRA) to examine the antiserum component of the among-laboratory variation in an international collaborative study with 28 laboratories evaluating a candidate international Reference Material (apo-RM) for apolipoproteins A-I (apo A-I) and B (apo B). Measurement of the relative concentration of lyophilized preparations differed by less than 1% for LA and IRA. The percentage of the total variation in measurement of the concentration of apo-RM that was contributed by antisera among laboratories was 5% and 8% for apo A-I and B, respectively. Estimated differences from overall mean concentrations for the five different immuno-methods were greater for apo B (range: +22% to -23.5%) than for apo A-I (range +14% to -14%), but were similar within a method for LA and IRA. The results indicated that antisera are not a major source of error among laboratories and, indeed, are responsible for relatively little of the total variability.
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40

Wolf, Wayne R., and Nancy J. Miller-Ihli. "Characterization of a mixed diet reference material (NBS RM 8431) for inorganic elements and selected organic nutrients." Fresenius' Zeitschrift für analytische Chemie 326, no. 7 (January 1987): 702–4. http://dx.doi.org/10.1007/bf00473534.

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41

Currie, L. A., and J. D. Kessler. "On the isolation of elemental carbon for micro-molar <sup>14</sup>C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material." Atmospheric Chemistry and Physics Discussions 5, no. 3 (May 26, 2005): 3341–66. http://dx.doi.org/10.5194/acpd-5-3341-2005.

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Анотація:
Abstract. The primary objective of the research reported here has been the development of an hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust), showed a range of results, but since the ''truth'' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC) of measurement validity (Currie et al., 2002). Components of the new Hybrid RM (DiesApple), however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically). NIST SRM 2975 (Forklift Diesel Soot) has little or no 14C, and its major compositional component is EC. SRM 1515 (Apple Leaves) has the 14C content of biomass-C, and it has little or no EC. Thus, the hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C from SRM 1515 in the EC isolate of the hybrid RM, together with testing for conservation of its dominant soot fraction through the isolation procedure.
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42

Shatalov, K. V., and L. A. Vlasenkova. "Method of composition justification of reference materials of motor fuels performance properties." Measurement Standards. Reference Materials 17, no. 4 (January 17, 2022): 33–46. http://dx.doi.org/10.20915/2687-0886-2021-17-4-33-46.

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Анотація:
At present, there are practically no reference materials for values characterizing the beneficial effect of the use of petroleum products, which reduces the efficiency of the metrological assurance processes for petroleum products testing. In particular, certification by the method of monitoring technical characteristics is an ineffective procedure for a number of motor sets and benches. It is necessary to assess the stability of such testing equipment relative to the s TABLE characteristics of any substance or material.Reference materials of motor fuels performance properties must comply with the requirements for the adequacy of the chemical composition of RM and motor fuels and guaranteed reproducibility of the values during the subsequent manufacture of a new batch of the reference material. In addition, reference materials should reproduce the values characteristic of a particular brand of commercial motor fuel or production technology.It was necessary to develop a method for justification of the composition of reference materials of motor fuels performance properties to meet the above requirements. The method includes the following stages: determination of the characteristic hydrocarbon composition of commercial motor fuels, selection of individual hydrocarbons of various groups, verification of their composition and basic physical and chemical properties, study of the most characteristic values of the investigated performance property and establishment of requirements for a possible measurement range of the certified value, measurement of the certified value for each individual hydrocarbon to be added to the composition of the reference material, development of a mathematical model «The composition of the mixture of individual hydrocarbons - The value of the motor fuel performance property» using experimental planning methods, calculation of the values of the concentrations of individual hydrocarbons in the mixture, providing the required certified value, experimental verification of the value of the certified characteristic of the performance property for the mixture with calculated values of the concentrations of individual hydrocarbons, correction of the calculated concentrations of individual hydrocarbons.The efficiency of the developed method is shown by the example of justification of the reference material composition of jet fuel chemical stability.
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43

Nuriel, Perach, Jörn-Frederik Wotzlaw, Maria Ovtcharova, Anton Vaks, Ciprian Stremtan, Martin Šala, Nick M. W. Roberts, and Andrew R. C. Kylander-Clark. "The use of ASH-15 flowstone as a matrix-matched reference material for laser-ablation U − Pb geochronology of calcite." Geochronology 3, no. 1 (January 14, 2021): 35–47. http://dx.doi.org/10.5194/gchron-3-35-2021.

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Abstract. Latest advances in laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) allow for accurate in situ U−Pb dating of carbonate material, with final age uncertainties usually >3 % 2σ. Cross-laboratory reference materials (RMs) used for sample-bracketing are currently limited to WC1 calcite with an age of 254.4±6.5 (2σ). The minimum uncertainty on any age determination with the LA-ICPMS method is therefore ≥2.5 %, and validation by secondary RMs is usually performed on in-house standards. This contribution presents a new reference material, ASH-15, a flowstone that is dated here by isotope dilution (ID) thermal ionization mass spectrometry (TIMS) analysis using 37 sub-samples, 1–7 mg each. Age results presented here are slightly younger compared to previous ID isotope ratio mass spectrometry (IRMS) U−Pb dates of ASH-15 but within uncertainties and in agreement with in situ analyses using WC1 as the primary RM. We provide new correction parameters to be used as primary or secondary standardization. The suggested 238U∕206Pb apparent age, not corrected for disequilibrium and without common-lead anchoring, is 2.965±0.011 Ma (uncertainties are 95 % confidence intervals). The new results could improve the propagated uncertainties on the final age with a minimal value of 0.4 %, which is approaching the uncertainty of typical ID analysis on higher-U materials such as zircon. We show that although LA-ICPMS spot analyses of ASH-15 exhibit significant scatter in their isotopic ratios, the down-hole fractionation of ASH-15 is similar to that of other reference materials. This high-U (≈1 ppm) and low-Pb (<0.01 ppm) calcite is most appropriate as a reference material for other speleothem-type carbonates but requires more-sensitive ICP-MS instruments such as the new generation of single-collector and multi-collector ICP-MS. Reference materials with high-Pb and low-U or both low-U and low-Pb compositions are still needed to fully cover the compositional range of carbonate material but may introduce analytical challenges.
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44

Guillong, Marcel, Jörn-Frederik Wotzlaw, Nathan Looser, and Oscar Laurent. "Evaluating the reliability of U–Pb laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) carbonate geochronology: matrix issues and a potential calcite validation reference material." Geochronology 2, no. 1 (June 30, 2020): 155–67. http://dx.doi.org/10.5194/gchron-2-155-2020.

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Abstract. We document that the reliability of carbonate U–Pb dating by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is improved by matching the aspect ratio of the LA single-hole drilling craters and propagating long-term excess variance and systematic uncertainties. We investigated the impact of different matrices and ablation crater geometries using U–Pb isotope analyses of one primary (WC-1) and two secondary reference materials (RMs). Validation RMs (VRMs) include a previously characterised one (ASH-15D) and a new candidate (JT), characterised by ID-TIMS (intercept age: 13.797±0.031 Ma) with excellent agreement to pooled LA-ICP-MS measurements (13.75±0.11 | 0.36 Ma), a U concentration of approx. 1 µg g−1 and 238U∕206Pb ratios from 5 to 460, defining the isochron well. Differences in ablation crater depth to diameter ratios (aspect ratio) introduce an offset due to downhole fractionation and/or matrix effects. This effect can be observed either when the crater size between U–Pb RM and the sample changes or when the ablation rate for the sample is different than for the RM. Observed deviations are up to 20 % of the final intercept age depending on the degree of crater geometry mismatch. The long-term excess uncertainty was calculated to be in the range of 2 % (ASH-15D) to 2.5 % (JT), and we recommend propagating this uncertainty into the uncertainty of the final results. Additionally, a systematic offset to the ID-TIMS age of 2 %–3 % was observed for ASH-15D but not for JT. This offset might be due to different ablation rates of ASH-15D compared to the primary RM or remaining matrix effects, even when the aspect ratios chosen are similar.
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45

Bachmann, Lorin M., Min Yu, James C. Boyd, David E. Bruns, and W. Greg Miller. "State of Harmonization of 24 Serum Albumin Measurement Procedures and Implications for Medical Decisions." Clinical Chemistry 63, no. 3 (March 1, 2017): 770–79. http://dx.doi.org/10.1373/clinchem.2016.262899.

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Abstract BACKGROUND Measurements of serum and plasma albumin are widely used in medicine, including as indicators of quality of patient care in renal dialysis centers. METHODS Pools were prepared from residual patient serum (n = 50) and heparin plasma (n = 48) from patients without renal disease, and serum from patients with kidney failure before hemodialysis (n = 53). Albumin was measured in all samples and in ERM-DA470k/IFCC reference material (RM) by 3 immunochemical, 9 bromcresol green (BCG), and 12 bromcresol purple (BCP) methods. RESULTS Two of 3 immunochemical procedures, 5 of 9 BCG, and 10 of 12 BCP methods recovered the RM value within its uncertainty. One immunochemical and 3 BCG methods were biased vs the RM value. Random error components were small for all measurement procedures. The Tina-quant immunochemical method was chosen as the reference measurement procedure based on recovery and results of error analyses. Mean biases for BCG vs Tina-quant were 1.5% to 13.9% and were larger at lower albumin concentrations. BCP methods' mean biases were −5.4% to 1.2% irrespective of albumin concentration. Biases for plasma samples were generally higher than for serum samples for all method types. For most measurement procedures, biases were lower for serum from patients on hemodialysis vs patients without kidney disease. CONCLUSIONS Significant differences among immunochemical, BCG, and BCP methods compromise interpretation of serum albumin results. Guidelines and calculations for clinical management of kidney and other diseases must consider the method used for albumin measurement until harmonization can be achieved.
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46

Sharma, Abhishek, Vyas Mani Sharma, and Jinu Paul. "Fabrication of bulk aluminum-graphene nanocomposite through friction stir alloying." Journal of Composite Materials 54, no. 1 (June 27, 2019): 45–60. http://dx.doi.org/10.1177/0021998319859427.

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Анотація:
Friction stir alloying is primarily employed for the fabrication of surface composite to improve surface properties like hardness, wear resistance, and corrosion resistance without significantly affecting the bulk properties of the alloy. The present study demonstrates the novel method for the fabrication of bulk aluminum-graphene nanoplatelets composite by using friction stir alloying. Here, the novelty is shown through the method of graphene nanoplatelets incorporation in the stir zone. For this purpose, a channel is fabricated on the cross-sectional surface of the aluminum plate and filled with graphene nanoplatelets. It is then covered by the cross-sectional surface of another aluminum plate of same dimensions and friction stir alloying is carried out. Reference material (RM) is also fabricated at the same parameters without any graphene nanoplatelet reinforcements for the performance evaluation of the nanocomposite. The microhardness of the fabricated composite increased by ∼57% as compared to the reference material. However, the tensile strength of the fabricated Al-graphene nanoplatelet composites decreased marginally as compared to reference material. The strengthening of the composite is explained systematically by various mechanisms. The results of microhardness and tensile test were corroborated with various characterization methods such as optical micrographs, scanning electron microscopy, atomic force microscope, and X-ray diffraction.
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47

Shehata, Adel B., Abdulrahman R. Alaskar, Mohammed A. Alrasheed, Abdullah S. Alosaimi, Fahd A. Alkharraa, and Abdulrahman M. Alzahrani. "Certification of sodium benzoate solution reference material by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometry for food and drug analysi." Journal of Chemical Metrology 14, no. 2 (November 28, 2020): 88–105. http://dx.doi.org/10.25135/jcm.48.20.08.1780.

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Анотація:
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.
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48

Zeraoui, Ahmed, Walid Maherzi, Mahfoud Benzerzour, Nor Edine Abriak, and Georges Aouad. "Development of Flash-Calcined Sediment and Blast Furnace Slag Ternary Binders." Buildings 13, no. 2 (January 23, 2023): 333. http://dx.doi.org/10.3390/buildings13020333.

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Partial cement replacement by low-carbon-impact additions has the potential to reduce CO2 emissions. The aim of this study is the development of a ternary binder that includes ordinary Portland cement (OPC), ground granulated blast furnace slag (GGBS), and flash-calcined sediment (FCS). To upgrade dredged mineral material into FCS, a new heat treatment, i.e., flash calcination, was used. The used materials were physically, chemically, and mineralogically characterized. The mixture design method was used to optimize the design of the ternary blended binders. A model was developed and validated for the prediction of the 90-day compressive strength for mortars composed of OPC (C), GGBS (S), and FCS (F). Five mixes, reference RM (100% OPC), binary mix (50% OPC and 50% GGBS), and three ternary mixes with FCS rates of 10%, 15%, and 20% were characterized in fresh and hardened states. The results show that the incorporation of FCS reduced the workability of the mixes and increased their densities. Moreover, the initial setting time of the mix was delayed, and the heat of the hydration peak was decreased. The 90-day compressive strengths of the mix containing 10% FCS were higher than those of RM. In conclusion, the use of 10% FCS and 40% GGBS was an efficient substitute for 50% OPC.
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49

García-Manrique, Pablo, Esther Serrano-Pertierra, Estefanía Lozano-Andrés, Soraya López-Martín, María Matos, Gemma Gutiérrez, María Yáñez-Mó, and María Carmen Blanco-López. "Selected Tetraspanins Functionalized Niosomes as Potential Standards for Exosome Immunoassays." Nanomaterials 10, no. 5 (May 18, 2020): 971. http://dx.doi.org/10.3390/nano10050971.

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Анотація:
Quantitative detection of exosomes in bio-fluids is a challenging task in a dynamic research field. The absence of a well-established reference material (RM) for method development and inter-comparison studies could be potentially overcome with artificial exosomes: lab-produced biomimetic particles with morphological and functional properties close to natural exosomes. This work presents the design, development and functional characteristics of fully artificial exosomes based on tetraspanin extracellular loops-coated niosomes, produced by bio-nanotechnology methods based on supra-molecular chemistry and recombinant protein technology. Mono- and double-functionalized particles with CD9/CD63 tetraspanins have been developed and characterized from a morphological and functional point of view. Produced bio-particles showed close similarities with natural entities in terms of physical properties. Their utility for bioanalysis is demonstrated by their detection and molecular-type discrimination by enzyme-linked immunosorbent assays (ELISAs), one of the most frequent bio-analytical method found in routine and research labs. The basic material based on streptavidin-coated niosomes allows the surface functionalization with any biotinylated protein or peptide, introducing versatility. Although promising results have been reported, further optimizations and deeper characterization will help this innovative biomaterial become a robust RM for validation and development of diagnostic tools for exosomes determination.
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50

Cieśla, M., R. Findziński, G. Junak, and T. Kawała. "The Effect of Heat Treatment Parameters on Mechanical Characteristics of 10CrMo9-10 Steel Tube Bends / Wpływ Parametrów Obróbki Cieplnej Na Charakterystyki Mechaniczne Łuków Rurowych Ze Stali 10CrMo9-10." Archives of Metallurgy and Materials 60, no. 4 (December 1, 2015): 2971–76. http://dx.doi.org/10.1515/amm-2015-0474.

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Анотація:
The purpose of the paper was to analyse the effect of diverse heat treatment parameters (normalising and tempering) on mechanical characteristics of the material used to develop ϕ508x20 tube bends made of the 10CrMo9-10 steel by application of induction heating. The research conducted included tests of basic mechanical properties as well as low cycle fatigue and creep at the temperature of 500°C. With reference to the results thus obtained, it has been established that there is a relationship between mechanical properties of bends and individual features of their microstructure conditional to the heat treatment parameters. Among other conclusions drawn in the research, it has been found that the main structural factor conditioning the mechanical properties of bends was the grain size. Heat treatment parameters characterised by lower temperature and shorter tempering time triggered changes in the material microstructure, such as increased grain comminution. The effects of the said changes included improvement of strength characteristics (Rm, Rp0,2) as well as increased material durability under conditions of fatigue and creep. Main criterion-specific mechanical properties and geometric features of the bends developed conformed with the relevant requirements of reference standards (PN-EN 10216-2, PN-EN 12952).
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