Graphic technology and photography. Certified reference materials for reflection and transmission metrology. Documentation and procedures for use, including determination of combined standard uncertainty

2015 ◽  
Keyword(s):  
Reference Materials ◽  
Certified Reference Materials ◽  
Standard Uncertainty ◽  
Reflection And Transmission

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

1992 ◽  
Vol 02 (04) ◽  
pp. 489-491 ◽  
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.

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

2014 ◽  
Vol 4 (1) ◽  
pp. 193 ◽  
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 &gt;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>

Evaluation of Automated Sample Preparation for Mycotoxin Analysis in Foods

2020 ◽  
Vol 103 (4) ◽  
pp. 1052-1059 ◽  
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&lt;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.

scholarly journals Estimate of Uncertainty of Measurement from a Single-Laboratory Validation Study: Application to the Determination of Lead in Blood

2004 ◽  
Vol 50 (8) ◽  
pp. 1396-1405 ◽  
Author(s):  
Marina Patriarca ◽  
Marco Castelli ◽  
Federica Corsetti ◽  
Antonio Menditto
Keyword(s):  
Reference Materials ◽  
Certified Reference Materials ◽  
Electrothermal Atomic Absorption Spectrometry ◽  
Absorption Spectrometry ◽  
Environmental Pollutant ◽  
The European Union ◽  
Lead In Blood ◽  
Method Performance ◽  
Target Values

Abstract Background: Lead is an environmental pollutant, and human exposure is assessed by monitoring lead concentrations in blood. Because the main source of environmental exposure has been the use of leaded gasoline, its phase-out has led to decreased lead concentrations in the general population. Therefore, validated analytical methods for the determination of lower lead concentrations in blood (&lt;150 μg/L) are needed. In addition, new ISO standards require that laboratories determine and specify the uncertainty of their results. Methods: We validated a method to determine lead in blood at concentrations up to 150 μg/L by electrothermal atomic absorption spectrometry with Zeeman background correction according to EURACHEM guidelines. Blood samples were diluted (1:1 by volume) with 2 mL/L Triton X-100. NH4H2PO4 (5 g/L) and Mg(NO3)2 (0.5 g/L) were used as modifiers. Matrix-matched standards were used for calibration. Results: We determined the limits of detection (3.1 μg/L) and quantification (9.4 μg/L). Repeatability and intermediate imprecision within the range 35–150 μg/L were &lt;5.5% and &lt;6.0%, respectively. We assessed trueness by use of certified reference materials, by recovery tests, and by comparison with target values of other reference materials (candidate external quality assessment samples). The expanded uncertainty ranged from 20% to 16% (with a confidence level of 95%) depending on concentration. Conclusions: This study provides a working example of the estimate of uncertainty from method performance data according to the EURACHEM/CITAC guidelines. The estimated uncertainty is compatible with quality specifications for the analysis of lead in blood adopted in the US and the European Union.

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