CERTIFICATION REPORT The certification of trace elements mass fraction in electrolytic copper: ERM®-EB074A, B and C

This report describes the production of ERM®-EB074A, B and C, a pure copper material with low level of added impurities certified for the mass fraction of Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn and Zr. The material was produced following ISO Guide 34:2009 [ ]. Pure copper was melted with pure metal and alloy to obtain a pure copper material with added impurities. After casting, the material was processed by hot extrusion and cold machining to produce discs of 39 mm diameter (ERM-EB074A), cylinders of 8 mm diameter (ERM-EB074B) and chips of 250 mg (ERM-EB074C). Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. Within-unit homogeneity was quantified to determine the minimum sample intake. The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025 [ ]. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity, and instability and to characterisation. The material is intended for the quality control and assessment of method performance. As any reference material, it can also be used for control charts or validation studies. The certified reference material (CRM) is available in three different formats: - ERM-EB074A: disc of 39 mm diameter; 30 mm thick; packed in box - ERM-EB074B: cylinder of 8 mm diameter; 100 mm length; sealed in plastic sachet under vacuum - ERM-EB074C: bottle of 50 grams of chips; chip weight 250 mg The minimum sample intake of ERM-EB074A and B is suitable for GD-MS and spark-OES techniques. For ERM-EB074C, the minimum amount of sample to be used is 20 mg for As, Ni, Pb, Sb, Se, Sn, Te; 100 mg for Ag, Al, Be, Bi, Cd, Co, Cr, Hg, In, Mg, Mn, Ti, W, Zn, Zr; 200 mg for Au, Fe; 300 mg for S and 500 mg for Si. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.D.2-Standards for Innovation and sustainable Developmen

Certification report - The certification of the gold mass fraction in Al-0.1%Au alloy: ERM®-EB530A, B and C

This report describes the production of ERM®-EB530A, B and C, aluminium gold alloy material certified for the mass fraction of gold. The material was produced following ISO Guide 34:2009. Pure aluminium and pure gold were arc melted together to obtain a master alloy Al-5%Au (mass percent). The master alloy was melted with pure aluminium in a resistance furnace, casted in ingot and heat treated. The ingot was processed mechanically (wire drawing or rolling) to obtain thin wire (diameter 0.5 mm and 1.0 mm) and thin foil (thickness 0.1 mm). Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. Within-unit homogeneity was quantified to determine the minimum sample intake. The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were estimated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity, and instability and to characterisation. The material is intended for the calibration of methods (k0-neutron activation analysis). As any reference material, it can also be used for control charts or validation studies. The CRM is packed in plastic boxes and available in three different versions: ERM-EB530A: foil of 50 cm2, thickness: 0.100 mm; ERM-EB530B: 1 meter of wire diameter 0.500 mm; ERM-EB530C: 1 meter of wire diameter 1.000 mm. The minimum amount of sample to be used is 0.55 mg. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.D.2-Standards for Innovation and sustainable Developmen

CERTIFICATION REPORT: The certification of trace elements mass fraction in electrolytic copper with added impurities: ERM®-EB075A, B and C

This report describes the production of ERM®-EB075A, B and C, a pure coppermaterial with added impurities certified for the mass fraction of Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn and Zr. The material was produced following ISO Guide 34:2009 [ ]. Pure copper was melted with pure metal and alloy to obtain a pure copper material with added impurities. After casting, the material was processed by hot extrusion and cold machining to produce discs of 39 mm diameter (ERM-EB075A), cylinders of 8 mm diameter (ERM-EB075B) and chips of 250 mg (ERM-EB075C). Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. Within-unit homogeneity was quantified to determine the minimum sample intake. The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025 [ ]. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity, and instability and to characterisation. The material is intended for the quality control and assessment of method performance. As any reference material, it can also be used for control charts or validation studies. The certified reference material (CRM) is available in three different formats: - ERM-EB075A: disc of 39 mm diameter; 30 mm thick; packed in box - ERM-EB075B: cylinder of 8 mm diameter; 100 mm length; sealed in plastic sachet under vacuum - ERM-EB075C: bottle of 50 g of chips; chip weight 250 mg The minimum sample intake of ERM-EB075A and B is suitable for GD-MS and spark-OES techniques. For ERM-EB075C, the minimum amount of sample to be used is 20 mg for As, Ni, Pb, Sb, Se, Sn, Te; 100 mg for Ag, Al, Be, Bi, Cd, Co, Cr, Hg, In, Mg, Mn, Sb, Se, Ti, W, Zr; 200 mg for Au, Be, Bi, Fe, Zn; 300 mg for sulphur and 500 mg for Si. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.JRC.D.2-Standards for Innovation and sustainable Developmen

Assessment of hydrogen quality dispensed for hydrogen refuelling stations in Europe

The fuel quality of hydrogen dispensed from 10 refuelling stations in Europe was assessed. Representative sampling was conducted from the nozzle by use of a sampling adapter allowing to bleed sample gas in parallel while refuelling an FCEV. Samples were split off and distributed to four laboratories for analysis in accordance with ISO 14687 and SAE J2719. The results indicated some inconsistencies between the laboratories but were still conclusive. The fuel quality was generally good. Elevated nitrogen concentrations were detected in two samples but not in violation with the new 300 μmol/mol tolerance limit. Four samples showed water concentrations higher than the 5 μmol/mol tolerance limit estimated by at least one laboratory. The results were ambiguous: none of the four samples showed all laboratories in agreement with the violation. One laboratory reported an elevated oxygen concentration that was not corroborated by the other two laboratories and thus considered an outlier.publishedVersio

Re-estimation of argon isotope ratios leading to a revised estimate of the Boltzmann constant

In 2013, NPL, SUERC and Cranfield University published an estimate for the Boltzmann constant [1] based on a measurement of the limiting low-pressure speed of sound in argon gas. Subsequently, an extensive investigation by Yang et al [2] revealed that there was likely to have been an error in the estimate of the molar mass of the argon used in the experiment. Responding to [2], de Podesta et al revised their estimate of the molar mass [3]. The shift in the estimated molar mass, and of the estimate of kB, was large: -2.7 parts in 106, nearly four times the original uncertainty estimate. The work described here was undertaken to understand the cause of this shift and our conclusion is that the original samples were probably contaminated with argon from atmospheric air.
 In this work we have repeated the measurement reported in [1] on the same gas sample that was examined in [2, 3]. However in this work we have used a different technique for sampling the gas that has allowed us to eliminate the possibility of contamination of the argon samples. We have repeated the sampling procedure three times, and examined samples on two mass spectrometers. This procedure confirms the isotopic ratio estimates of Yang et al [2] but with lower uncertainty, particularly in the relative abundance ratio R38:36.
 Our new estimate of the molar mass of the argon used in Isotherm 5 in [1] is 39.947 727(15) g mol-1 which differs by +0.50 parts in 106 from the estimate 39.947 707(28) g mol-1 made in [3]. This new estimate of the molar mass leads to a revised estimate of the Boltzmann constant of kB = 1.380 648 60 (97) × 10−23 J K−1 which differs from the 2014 CODATA value by +0.05 parts in 106.&#13

Certification of the mass concentration of arsenic, cadmium, chromium, copper, iron, manganese, mercury, lead, nickel and selenium in wastewater: ERM®-CA713

The report describes the production and certification of the certified reference material ERM-CA713 Wastewater. The material was produced to replace the existing materials BCR-713, BCR-714 and BCR-715 because of changes in the legislation, in particular the requirement for the monitoring of Hg as a priority substance. The material is certified for As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Se. and will serve as a quality control tool for the laboratories involved in the mandatory monitoring of the Priority Substances prescribed under the Water Framework Directive (WFD, 2000/60/EC).JRC.D.2-Standards for Innovation and sustainable Developmen

The certification of the mass fraction of carbon in cementite grains in a Fe-C matrix: IRMM-471

The report describes the production and certification of IRMM-471, a reference material certified for the carbon mass fraction of its cementite (Fe3C) grains. The Fe3C grains are dispersed within an iron pearlite matrix and present an average grain diameter between 20 µm and 50 μm. IRMM-471 has been produced and certified in order to be used as calibrant in electron probe micro-analyser (EPMA) for carbon determination in iron and steel products.JRC.D.2-Standards for Innovation and sustainable Developmen

Production and stability of low amount fraction of formaldehyde in hydrogen gas standards

Formaldehyde is an intermediate of the steam methane reforming process for hydrogen production. According to International Standard ISO 14687-2 the amount fraction level of formaldehyde present in hydrogen supplied to fuel cell electric vehicles (FCEV) must not exceed 10 nmol mol−1. The development of formaldehyde standards in hydrogen is crucial to validate the analytical results and ensure measurement reliability for the FCEV industry. NPL demonstrated that these standards can be gravimetrically prepared and validated at 10 μmol mol−1 with a shelf-life of 8 weeks (stability uncertainty <10%; k = 1), but that formaldehyde degrades into methanol and dimethoxymethane, as measured by FTIR, GC-MS and SIFT-MS. The degradation kinetics is more rapid than predicted by thermodynamics, this may be due to the internal gas cylinder surface acting as a catalyst. The identification of by-products (methanol and dimethoxymethane) requires further investigation to establish any potential undesirable impacts to the FCEV

Alternative designs for the assessment of homogeneity: Use of characterisation data

In order to reduce analysis cost and save samples, the homogeneity study of two titanium certified reference materials was combined with the interlaboratory characterisation of that material. Samples were selected using a random stratified sampling scheme and were sent to 9 and 11 laboratories, respectively. The data were normalised to screen for trends in the production sequence, outliers and normality of the distribution of sample means. The non-normalised data were screened for outlying variances and the uncertainty of homogeneity was evaluated using 2-way analysis of variance. The uncertainty contributions determined were in all cases significant, but did usually not dominate the uncertainty of the assigned value. The findings were confirmed by a homogeneity study with a limited scope on one of the two materials. While the assessment of homogeneity using the approach was successful, the goal of reducing the consumption of samples and reducing analytical cost was only partially realised: similar number of samples were consumed and 5-10 % lower analytical cost than in a classical, i.e. separate homogeneity and characterisation study setup, were incurred.JRC.F.6-Reference Material