The need for quality assessment of anthropogenic impact on environmental pollution is increasing due to discharge from various industries, the use of chemicals in agriculture and the consumption of fossil fuels. Diminishing resources such as natural waters used for the cultivation of agricultural products, plant and animal habitats are under severe pollution pressure and are at constant risk. Several parameters, such as Pb, Cd, Ni, Hg were listed by Water Framework Directive in Directive (2008/105/EC) in the priority substances. Cadmium and Hg were identified as priority hazardous substances whereas As is an important contaminant for its potential toxicological and carcinogenic effects. An inter-comparison study is organised in EURAMET TC-MC in order to demonstrate the capability participants for measuring five elements in river water. The participants carried out measurements for analytes: Pb, Cd, Ni and As as mandatory elements, and Se as an optional one. Participants were asked to perform the measurements with respect to the protocol provided. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
During archaeological campaigns in 2010, 2012 and 2015 at the Medieval necropolis Crkvina, in central Bosnia, beside skeletal remains, pieces of jewelry, ceramic, construction material, fabric and small artefacts from different periods were also found. The most important finding was a signet ring, with the lily motif, believing to belong to Bosnian king or some high class nobility from Medieval period. Beside the ring, other richly decorated silver and gold jewelry was also found. The goal of this study was, for the first time, to provide information about composition of the most interesting artefacts and also to enhance knowledge about Medieval jewelry industry in Bosnian Kingdom. Results showed that the majority of jewelry was made from silver, of highest quality, with gold being used for surface gilding. Higher than usual copper content in some of the rings (more than 3% in weight percentage) was possibly added intentionally, to enhance properties of the silver. One of the rings, without any decorations was proved to be brass made, with zinc content as high as almost 20%. Results of this study contribute to the better understanding of the otherwise previously scarce knowledge of jewelry tradition in Medieval Bosnian Kingdom.
The accurate quantification of ethanol in water is essential for forensic applications such as blood and breath alcohol testing and for commercial applications such as the assessment of alcoholic beverages. The intercomparison EURAMET.QM-S14 is part of a capacity building project named ALCOREF "Certified forensic alcohol reference materials" [1] that is running within the European Metrology Programme for Innovation and Research (EMPIR) [2]. The intercomparison should allow project partners and other interested National Metrology Institutes (NMIs) and Designated Institutes (DIs) to benchmark their analytical methods for the quantification of ethanol in water. The study plan was agreed by the European Association of National Metrology Institutes (EURAMET) Subcommittee Bio- and Organic Analysis (SCBOA) and the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) in February and April 2019, respectively. The intercomparison was coordinated by BAM. Two concentration levels relevant for the calibration and verification of evidential breath alcohol analysers were distributed to study participants. Fifteen institutes from 15 countries registered for the intercomparison and returned results. Participants mostly applied gas chromatography with flame ionisation detection (GC-FID) or mass spectroscopy (GC-MS), one participant used titrimetry and one participant employed a test bench for breath analyser calibration ("bubble train"). Participants did either in-house purity assessment of their commercial ethanol calibrants by Karl-Fischer titration, chromatographic methods, quantitative nuclear magnetic resonance spectroscopy (qNMR) and/or density measurements; or they used ethanol/water Certified Reference Materials (CRMs) from NMIs/DIs for calibration. CCQM OAWG agreed to use a consensus value from participants' results that utilizes the reported uncertainties as Key Comparison Reference Value (KCRV). The Gaussian Random effects model with Hierarchical Bayesian solution (HB-REM) is a reasonable approach in this case. The KCRVs and Degrees of Equivalence (DoEs) were calculated with the NIST consensus builder version 1.2 Hierarchical Bayes procedure [3]. Successful participation in the interlaboratory comparison has demonstrated the capabilities in determining the mass fraction of ethanol in aqueous matrices in the range 0.1 mg/g to 8 mg/g. Fourteen out of 15 participants have successfully quantified both samples, one participant successfully quantified only the lower-level (0.6 mg/g) sample. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Sa izdavanjem standarda ISO/IEC 17025:1999 procjena mjerne nesigurnosti je postala obaveza kompetentnih ispitnih laboratorija. Taj zahtjev je zajednicu analiticara stavio pred težak zadatak u odabiru adekvatnog pristupa za realnu procjenu mjerne nesigurnosti. Klasican pristup koji je promovirao GUM je bio tesko primjenjljiv na kompleksne hemijske analiticke procese, te je pozdravljen moderan empirijski pristup utemeljen standardom ISO/TS 21748:2004. U ovom strucnom radu su navedeni rezultati primjene klasicnog pristupa modeliranja i empirijskog pristupa za procjenu mjerne nesigurnosti rezultata jednostavne volumetrijske metode za određivanje sadržaja srebra sa svrhom procjene realnosti dobijenih kvantifikacija. Ispitivani uzorci su srebrene legure za nakit ciji je kvalitet specificiran tehnickom legislativom i sa tog stanovista je znacajno uz rezultat ispitivanja izraziti njegovu mjernu nesigurnost. U prvom dijelu su izvori nesigurnosti definisani i kvantificirani na nacin preporucen u QUAM-u. Prilikom kvantifikacije koristeni su dostupni podaci o mjeriteljskim karakteristikama koristene mjerne opreme, a podaci o preciznosti su eksperimentalno procijenjeni. Dobijen je krajnji rezultat za ukupnu mjernu nesigurnost od 1,15 mg/g Ag. Empirijski pristup je zasnovan na eksperimentalnoj procjeni unutarlaboratorijske standardne devijacije reproduktivnosti i procjeni doprinosa od biasa koja je utvrđena poređenjem dobijenog rezultata sa rezultatom referentne (standardne) ispitne metode. Ukupna mjerna nesigurnost dobijena ovim pristupom je 1,18 mg/g Ag te je ustanovljeno da nema bitne razlike u kvantifikacijama koja su proizasla od primjene razlicitih pristupa za procjenu. Ovaj eksperiment ukazuje da kod pravilnog promisljanja i koristenja raspoloživih podataka nema disproporcije između procjene po ova dva razlicita pristupa te se laboratorija može odluciti da odabere onaj za koji posjeduje dovoljno podataka, resursa i znanja.
Nema pronađenih rezultata, molimo da izmjenite uslove pretrage i pokušate ponovo!
Ova stranica koristi kolačiće da bi vam pružila najbolje iskustvo
Saznaj više