Reference Materials in Chemical Measurements

Author(s):  
Ewa Bulska
2020 ◽  
Vol 13 (1) ◽  
pp. 453-474
Author(s):  
Steven J. Choquette ◽  
David L. Duewer ◽  
Katherine E. Sharpless

The National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards, was established by the US Congress in 1901 and charged with establishing a measurement foundation to facilitate US and international commerce. This broad language provides NIST with the ability to establish and implement its programs in response to changes in national needs and priorities. This review traces some of the changes in NIST's reference material programs over time and presents the NIST Material Measurement Laboratory's current approach to promoting accuracy and metrological traceability of chemical measurements and validation of chemical measurement processes.


1968 ◽  
Vol 14 (10) ◽  
pp. 929-943 ◽  
Author(s):  
Donald S Young ◽  
Thomas W Mears

Abstract The concepts of the measurement system based upon four parameters—length (meter), mass (kilogram), time (second), and temperature (kelvin)—are developed. The proper daily operation of an analytic laboratory depends upon these basic measurements and others derived from them, e.g., the liter. An additional component of chemical measurement which directly influences accuracy is the purity of the standards and reagents employed. The standard reference materials program of the National Bureau of Standards provides a central source of guaranteed high-purity reference materials which are available to all. The reliability of chemical measurements should increase as new standard reference materials such as cholesterol, uric acid, urea, and creatinine are utilized to standardize methods and to calibrate instruments in the clinical laboratories of this country.


2021 ◽  
Vol 17 (2) ◽  
pp. 33-47
Author(s):  
I. E. Vasil’eva ◽  
E. V. Shabanova

The population needs reliable information on the chemical composition of plants and products made from them in order to preserve the environment and its safety. With the increase in cross-border trade, there is a growing demand for traceable results of determining the content of chemical elements in plants and not only proteins, fats, carbohydrates, pesticides, moisture, vitamins, etc., which can affect the quality of human life. An urgent but difficult analytical task is to obtain reliable measurements of the elemental composition of agricultural and wild plants and various products made from them. Reference materials (RMs) are a widely recognized tool for ensuring the uniformity of chemical measurements. They are designed for certification (validation) of existing and new methods (techniques) of chemical analysis, certification studies in the development of reference materials, and professional testing of laboratories. The article lists the reputable manufacturers of plant RMs in which the content of chemical elements is certified. The ratio of certified, reference, and quality control samples of plant-matrix has been assessed. The classification of certified reference materials according to the type of plant material used for their food application is provided. The contribution of different countries to the development of plant CRMs is hown. The selection of plants for the development of new RMs is discussed from two points of view, namely food composition databases (AOAC INTERNATIONAL) and the ‘Reference Plant’ chemical fingerprinting (B. Markert). Based on the consolidation of studies devoted to the development and appliance of plant-matrix reference materials, a list of the most important requirements has been compiled for reference materials that ensure the reliability and comparability of the results of chemical analysis in the fields of biology, geochemistry, ecology, agriculture, medicine, and interdisciplinary research.


2021 ◽  
Vol 17 (3) ◽  
pp. 45-61
Author(s):  
E. V. Shabanova ◽  
I. E. Vasil’eva ◽  
D. S. Tausenev ◽  
S. Scherbarth ◽  
U. Pierau

Four multielement reference materials compile the «Plants» cluster in the developed by IGC SB RAS collection. These are part of terrestrial plants (birch leaf, pine needles, mown meadow grass) and the aquatic plant Elodea canadensis (roots, stems, leaves and flowers). Plants that are sensitive indicators of the state of the environment are collected from unpolluted territories of Eastern Siberia (near and on Lake Baikal). The paper discusses differences in methods of selection and preparation of the material. Such features of these reference materials as granulometric composition (shape, size, particle size distribution), homogeneity and minimum representative mass of the sample, stability ofpowders under conditions of natural aging were studied in accordance with Russian and international requirements with the use of modern devices and methods of chemical analysis. The elemental compositions of matrix plant samples were evaluated according to the method of interlaboratory certification and are represented by the contents of more than 60 elements, of which 23 to 41 are certified. The participation of 20 to 38 accredited Russian and foreign laboratories and the use of more than ten different methods of analysis ensured the traceability of the results. The comparison of the developed and Chinese certified matrix plant reference samples demonstrated their consistency. Based on the results of the discussion of the characteristic properties offour plant PM, they are recommended for performing chemical measurements during the validation of existing and development of new analytical methods, quality control and evaluation of the traceability of the results of determining a wide range of elements in plant materials, as well as professional testing of laboratories of geo-ecological, pharmaceutical and agricultural organisations.


Author(s):  
G. Remond ◽  
R.H. Packwood ◽  
C. Gilles ◽  
S. Chryssoulis

Merits and limitations of layered and ion implanted specimens as possible reference materials to calibrate spatially resolved analytical techniques are discussed and illustrated for the case of gold analysis in minerals by means of x-ray spectrometry with the EPMA. To overcome the random heterogeneities of minerals, thin film deposition and ion implantation may offer an original approach to the manufacture of controlled concentration/ distribution reference materials for quantification of trace elements with the same matrix as the unknown.In order to evaluate the accuracy of data obtained by EPMA we have compared measured and calculated x-ray intensities for homogeneous and heterogeneous specimens. Au Lα and Au Mα x-ray intensities were recorded at various electron beam energies, and hence at various sampling depths, for gold coated and gold implanted specimens. X-ray intensity calculations are based on the use of analytical expressions for both the depth ionization Φ (ρz) and the depth concentration C (ρz) distributions respectively.


2020 ◽  
pp. 66-72
Author(s):  
Irina A. Piterskikh ◽  
Svetlana V. Vikhrova ◽  
Nina G. Kovaleva ◽  
Tatyana O. Barynskaya

Certified reference materials (CRM) composed of propyl (11383-2019) and isopropyl (11384-2019) alcohols solutions were created for validation of measurement procedures and control of measurement errors of measurement results of mass concentrations of toxic substances (alcohol) in biological objects (urine, blood) and water. Two ways of establishing the value of the certified characteristic – mass consentration of propanol-1 or propanol-2 have been studied. The results obtained by the preparation procedure and comparison with the standard are the same within the margin of error.


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