On the use of certified reference materials for assuring the quality of results for the determination of mercury in environmental samples

AbstractDetermination of thallium in polluted environmental samples and their extracts obtained by a modified BCR three-step sequential extraction procedure was used to study thallium distribution and mobility in the monitored polluted area affected by acidification (Šobov, Central Slovakia). The results of fractionation applied to 5 soil certified reference materials and 14 environmental samples show that the vast majority of thallium occurred in the residual fraction. This means that highly toxic thallium is strongly entrapped in the parent rock materials remains immobile and its environmental toxicity is therefore reduced. The limit of detection for thallium in the studied fractions was lower than 0.050 mg kg−1, the precision (RSD) of the ultratrace determination of thallium in the studied fractions was better than 17 % and the accuracy of the used method was verified by analyzing certified reference materials.

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European certified reference materials (EURONORMCRMs) for the determination of the chemical composition of iron and steel products

10.3403/30392726 ◽

2020 ◽

Keyword(s):

Chemical Composition ◽

Reference Materials ◽

Certified Reference Materials ◽

Iron And Steel

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APPLICATION OF AAS AND NAA FOR DETERMINATION OF TIN IN SRMs, AND IN ANIMAL AND HUMAN ORGANS

International Journal of PIXE ◽

10.1142/s012908359200052x ◽

1992 ◽

Vol 02 (04) ◽

pp. 489-491 ◽

Cited By ~ 1

Author(s):

MOMOKO CHIBA ◽

VENKATESH G. IYENGAR

Keyword(s):

Neutron Activation Analysis ◽

Activation Analysis ◽

Reference Materials ◽

Certified Reference Materials ◽

Analytical Techniques ◽

Absorption Spectrometry ◽

Dry Weight ◽

Mixed Diet ◽

Human Organs

Tin (Sn) is one of the causative elements of the environmental pollution. As no certified reference materials for Sn are presently available, existing reference materials were analyzed for Sn by two independent analytical techniques; atomic absorption spectrometry (AAS) and neutron activation analysis (NAA). The results obtained by both methods were in agreement except for mixed diet which contains Sn in the range of 50 μ g/g. Further, tin concentrations in human and animal organs have been examined by AAS. Among organs tested tin concentrations in testes were the highest, 2.08±0.62 μ g/g dry weight (mean ±SD, n=12) in humans, and 1.45±0.55 μ g/g (n=8) in mice.

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Cost-effective Method of Analysis for the Determination of Cadmium, Copper, Nickel and Zinc in Cocoa Beans and Chocolates

Journal of Food Research ◽

10.5539/jfr.v4n1p193 ◽

2014 ◽

Vol 4 (1) ◽

pp. 193 ◽

Cited By ~ 5

Author(s):

Gideon Ramtahal ◽

Ivan Chang Yen ◽

Isaac Bekele ◽

Frances Bekele ◽

Lawrence Wilson ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Reference Materials ◽

Certified Reference Materials ◽

Control Sample ◽

Cost Effective ◽

Cocoa Beans ◽

Copper Nickel ◽

Flame Atomic Absorption

<p>The determination of heavy metals in cocoa beans and chocolates is of great importance, due to increasingly stringent regulations being implemented by international legislative bodies and chocolate manufacturers, to protect the health of their consumers. While various techniques exist for heavy metal analyses in cocoa, this study developed a cost-effective, accurate and precise method capable of processing up to 120 samples per batch for the determination of cadmium, copper, nickel and zinc. For sample extractions, a normal laboratory hot plate and locally fabricated high-capacity digestion blocks were used, instead of dedicated block digestion or microwave digestion systems. In addition, only concentrated nitric acid was used, instead of mixed reagents used in standardized methods, for metal extractions from samples, with a sample: extractant ratio of 0.5 g : 10 mL, digestion at 130 ºC, followed by filtration and analysis by flame atomic absorption spectrophotometry. The method was validated with Certified Reference Materials, with heavy metal recoveries generally >95%. Additionally, an in-house quality control sample of ground cocoa nib analyzed together with the Certified Reference Materials was used to monitor the consistency of analyses of heavy metals in cocoa bean samples.</p>

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The problem of improving the quality of seriously issued certified reference materials of the composition of gas mixtures

Reference materials ◽

10.20915/2077-1177-2019-15-3-5-13 ◽

2019 ◽

Vol 15 (3) ◽

pp. 5-13

Author(s):

L. A. Konopelko ◽

A. V. Kolobova ◽

O. V. Fatina

Keyword(s):

Reference Material ◽

Reference Materials ◽

Certified Reference Materials ◽

Metrological Traceability ◽

Gas Mixtures ◽

Measuring Instruments ◽

Expanded Uncertainty ◽

Iso Guide 35 ◽

The Russian Federation

Currently, in the Russian Federation, the metrological traceability of certified reference materials of the composition of gas mixtures in cylinders under pressure produced by manufacturers of certified reference materials is carried out in accordance with GOST 8.578-2014. Considering that certified reference materials of the composition of gas mixtures in cylinders under pressure are used for testing to approye the type of measuring instruments, verification, calibration, and graduation of gas-analytical measuring instruments used to control explosive gases and vapors, harmful components in the atmospheric air and the air of the working area, emissions from vehicles and enterprises, to control technological processes, the quality of hydrocarbon products, etc., the issue of ensuring the quality of seriously produced certified reference materials (about 100.000 cylinders with gas mixtures per year) is important. To ensure the quality of certified reference materials of gas mixtures in cylinders under pressure, mass-produced by manufacturers of certified reference materials, we offer the following actions:– manufacturers of certified reference materials’ passing of mandatory accreditation for compliance with the requirements of GOST ISO Guide 34–2014 and GOST ISO Guide 35–2015;– manufacturers of certified reference materials’ constant participation in the proficiency testing programs through interlaboratory tests;– actualizing and refining the existing set of standards defining the requirements for the entire life cycle of a certified reference material of a gas mixture in a cylinder under pressure;– improving the method of certification of a reference material by calculating the value of the expanded uncertainty of the reference material and the introducting a new coefficient «technological reserve».

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Application of a sequential extraction scheme to ten geological certified reference materials for the determination of 20 elements

Journal of Analytical Atomic Spectrometry ◽

10.1039/ja9961100787 ◽

1996 ◽

Vol 11 (9) ◽

pp. 787 ◽

Cited By ~ 85

Author(s):

Gwendy E. M. Hall ◽

Gilles Gauthier ◽

Jean-Claude Pelchat ◽

Pierre Pelchat ◽

Judy E. Vaive

Keyword(s):

Sequential Extraction ◽

Reference Materials ◽

Certified Reference Materials ◽

Extraction Scheme ◽

Sequential Extraction Scheme

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Development, validation, and certification by isotope dilution gas chromatography-mass spectrometry of lyophilized human serum reference materials for cortisol (CRM 192 and 193) and progesterone (CRM 347 and 348)

Clinical Chemistry ◽

10.1093/clinchem/37.4.540 ◽

1991 ◽

Vol 37 (4) ◽

pp. 540-546 ◽

Cited By ~ 34

Author(s):

Linda Thienpont ◽

Lothar Siekmann ◽

Alexander Lawson ◽

Elisabeth Colinet ◽

Andrȳ De Leenheer

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Reference Materials ◽

Isotope Dilution ◽

Certified Reference Materials ◽

Collaborative Study ◽

Gas Chromatography Mass Spectrometry ◽

Chromatography Mass Spectrometry ◽

Coefficients Of Variation

Abstract The Community Bureau of Reference of the European Communities has produced four batches of lyophilized serum Certified Reference Materials, two for cortisol (CRM 192 and 193) and two for progesterone (CRM 347 and 348). For cortisol, one of the pools consisted of serum from healthy blood donors, whereas the second batch was supplemented with pure cortisol. The progesterone Reference Materials contained only endogenous hormone concentrations. Assessment of vial-to-vial variability in the cortisol and progesterone concentrations showed no between-sample inhomogeneity, and the materials were stable. The quality of the materials was therefore considered sufficient for certification of the values for the cortisol and progesterone concentrations by a collaborative study involving several laboratories from the European Communities, using isotope dilution gas chromatography-mass spectrometry. Inaccuracy in reconstitution of the lyophilized materials was less than 0.3%; imprecision of sampling was less than 0.2%. For determinations of cortisol and progesterone concentrations, the mean within-laboratory coefficients of variation (CVs) were 1.76% (CRM 192), 1.19% (CRM 193), 1.64% (CRM 347), and 1.75% (CRM 348). The between-laboratory CVs were greater: CRM 192, 1.79%; CRM 193, 1.48%; CRM 347, 2.08%; and CRM 348, 2.16%. The concentrations in the reconstituted Reference Materials were certified to be 273 nmol/L in CRM 192 and 763 nmol/L in CRM 193 for cortisol and 10.13 nmol/L in CRM 347 and 40.3 nmol/L in CRM 348 for progesterone. Uncertainties at the 0.95 confidence level--6 (CRM 192), 14 (CRM 193), 0.21 (CRM 347), and 1.0 nmol/L (CRM 348)--were considered compatible with the intended use of the materials.

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Quality Assurance of Analytical Measurements—A Vital Element in Safety Performance in the Nuclear Field

Proceedings ◽

10.3390/proceedings2020055002 ◽

2020 ◽

Vol 55 (1) ◽

pp. 2

Author(s):

Elena Neacsu

Keyword(s):

Quality Assurance ◽

Reference Materials ◽

Certified Reference Materials ◽

Analytical Data ◽

Physical Principle ◽

Energy Agency ◽

Nuclear Domain ◽

Analyte Detection ◽

Harmful Effects

The (International Atomic Energy Agency) IAEA’s fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. The safety principles apply to all facilities and all activities to reduce existing radiation risks. Analytical quality assurance has gained in importance in many scientific areas, including the analysis of radioactive specimens that require a thorough investigation and regulations for safety and ecological reasons. The use of certified reference materials is an essential pillar for the assessment of the quality of analytical data. Still, such matrix-matched certified reference materials are unfortunately not available for most investigations relevant to the nuclear domain. Therefore, other strategies have to be established, i.e., to compare the analytical results obtained for a particular instrumental technique, with data from another methodology whose analyte detection is based on a different physical principle.

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Evaluation of Automated Sample Preparation for Mycotoxin Analysis in Foods

Journal of AOAC International ◽

10.1093/jaoacint/qsz044 ◽

2020 ◽

Vol 103 (4) ◽

pp. 1052-1059 ◽

Cited By ~ 1

Author(s):

Kai Zhang

Keyword(s):

Sample Preparation ◽

Reference Materials ◽

Certified Reference Materials ◽

Peanut Butter ◽

Method Performance ◽

Robotic Arms ◽

Automated Sample Preparation ◽

Sample Preparation Procedure ◽

Mycotoxin Analysis

Abstract Background In the present study, we developed a novel automated sample preparation workflow for the determination of mycotoxins in foods. Objective This workflow integrates off-line devices such as a centrifuge, shaker, liquid and solid dispensing units into a unified platform to perform gravimetric and volumetric dispensing, capping/decapping, extraction, shaking, filtration, and centrifugation. Two robotic arms provide sample transportation without human assistance. Method Critical method performance attributes were characterized using spiked corn, milk and peanut butter containing aflatoxins, deoxynivalenol, fumonisins, ochratoxin A, HT-2 and T-2 toxins and zearalenone and certified reference materials. Prepared samples were analyzed by liquid chromatography mass spectrometry (LC-MS). Results Recoveries of spiked samples range 100–120% with RSD<20% and the majority of measured values of certified reference materials are consistent with certified values within ±20%. Within- and between-batch variabilities of QC samples range 5–9% and 7–12% respectively. Conclusions Our workflow introduces a straightforward and automated sample preparation procedure for LC-MS-based multimycotoxin analysis. Further, it demonstrates how individual sample preparation devices, that are conventionally used off-line, can be integrated together. Highlights This study shows automated sample preparation will replace manual operations and significantly increase the degree of automation and standardization for sample preparation.

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