Search results for "Reference materials"
showing 7 items of 47 documents
Goldschmidt Abstracts 2010 – F
2010
We report on two novel procedures for the determination of several trace elements in seawater, including elements characterized by very low abundance (sub-0.1 to 1 ng l-1) in the ocean, such as REEs, Hf, and Th. Our methods are based on the procedure developed recently by Bayon et al. [1], and applied successfully to a wide range of geological samples. It involves addition of a Tm spike and pre-concentration using co-precipitation, prior to analysis by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The addition of a small amount of Tm to the sample produces a positive Tm anomaly in the resulting REE pattern, which allows calculation of precise trace element concentrat…
Food and Environment: Trace Element Content of Hen Eggs from Different Housing Types
2013
AbstractEleven trace elements (Ba, Cu, Fe, Mn, Ni, Pb, Rb, Se, Sr, V, Zn) were quantitatively determined in hen egg samples collected from different poultry housing types (large-scale poultry farms, organic farms and domestic farms) over the territory of Latvia. Samples were wet digested and quantitatively analysed by total reflection X-ray fluorescence spectrometry (TXRF). The accuracy of analytical method was verified with analysis of certified reference material NCS ZC73017 (GSB-10)-Apple. The most variable range of concentrations and the highest content of elements were determined for hen egg samples derived from organic farms, while egg samples from domestic farms and poultry farms mos…
The International Measurement Evaluation Programme (IMEP) IMEP-6: "Trace elements in water"
1998
The sixth round of the International Measurement Evaluation Programme (IMEP) is presented. The programme offers reference values, established by primary methods of measurement, against which participating laboratories can evaluate their performance. The degree of comparability is thus established against the most objective references available at present. In IMEP-6, reference values for total concentrations of 14 trace elements in a synthetic and a natural water were established mainly by isotope dilution mass spectrometry (IDMS). For the majority of the measurands, results traceable to the international system of units (SI) and having expanded uncertainties, U (k=2), of 2% could be establi…
Développement de méthodes de référence pour les biomarqueurs du bilan lipidique : application au contrôle qualité en biologie clinique
2013
Reliable measurements in medical biology are essential for early screening and appropriate follow-up of patients. Ensuring metrological traceability of clinical measurements to higher order reference methods or certified reference materials enables to obtain comparable results over time and between different laboratories that could use different methods to quantify the same biomarker.In this study, reference methods were developed and validated for lipid profile biomarkers (total cholesterol, triglycerides, HDL-C, and LDL-C). Their value added in proficiency testing schemes was demonstrated against consensus mean. They were also used to characterize a certified reference material (CRM) that…
A novel scientific approach to the conservation of archaeological copper alloys artefacts
2007
A novel research approach focused on innovative materials and methods to assure the long-term stability of bronze archaeological artefacts during exhibition and storage is reported. The work deals with the application of advanced analytical techniques and the development, characterisation and testing of materials and procedures for the conservation, protection and restoration of ancient Cu-based alloy artefacts. Our first aim was the selection of Cu-based alloy artefacts from different archaeological sites in Southern Italy with respect of chemical composition, metallurgical features and corrosion products. This step allowed the identification of the ancient alloys, the study of natural pat…
Method for Reproducible Shipboard Segmented Flow Analysis Ammonium Measurement Using an In-House Reference Material for Quality Control
2021
Ammonium is a fundamental nutrient for phytoplankton growth in seawater and is a key component of the microbial loop. Ammonium measured in parallel with other nutrients is crucial in understanding the small temporal scale changes in oceanographic ecology. Despite the importance of measuring ammonium at sea, owing to its lability, there is no consensus on the best method. The lack of availability of certified reference materials for ammonium in seawater also makes it difficult to assess the accuracy and reproducibility of ammonium measurements. In this study we present a modified segmented flow analysis method using ortho-phthaldialdehyde (OPA) with fluorescence detection to measure ammonium…
Determination of metal concentrations in certified plastic reference materials after small-size autoclave and microwave-assisted digestion followed w…
2017
Abstract The digestion methods for the determination of As, Cd, Cr, Pb, Sb, Sn and Zn concentrations in plastic samples using microwave-assisted digestion (MW-AD) and small-size autoclave digestion was developed. The certified polyethylene, polypropylene, polyvinyl chloride and acrylonitrile butadiene styrene certified reference materials were used in order to find digestion method working properly for several sample matrices. Efficiency of the digestion methods was evaluated by analyzing the residual carbon in digests by TOC analyzer. MW-AD using a mixture of 7 mL of HNO 3 and 3 mL of H 2 O 2 as a digestion solution resulted in excellent recoveries for As, Cd, Pb, Sb and Zn, and were in th…