Results of the First EC/OC Comparison Exercise for EU National Air Quality Reference Laboratories (AQUILA)

The JRC-IES European Reference Laboratory for Air Pollution (ERLAP) has organized an inter-laboratory comparison for the measurement of elemental carbon (EC) and organic carbon (OC) in particulate matter sampled on filters. To this comparison European Union National Reference Laboratories for air quality or delegated organizations have participated, all using instrumentation of the same make (Sunset Laboratories Inc. ). The objectives of this comparison have been to evaluate the performances of participants but also to study the effects of the use of different thermal analysis protocols currently used for analysis. It has been shown – based on z-scores – that all participants using laboratory analyzers are able to meet a 25% expanded uncertainty as a “fitness-for-purpose” criterion for total carbon (TC, as the sum of OC and EC) and OC. For EC this criterion is only met when results are evaluated by specific protocols (NIOSH or EUSAAR_2) separately. Field versions of the analyzer have been found for a number of samples to yield aberrant results.JRC.H.2-Air and Climat

Elemental and Organic Carbon in PM10: a One Year Measurement Campaign within the European Monitoring and Evaluation Programme EMEP

In the present study, ambient aerosol (PM10) concentrations of elemental carbon (EC), organic carbon (OC), and total carbon (TC) are reported for 12 European rural background sites and two urban background sites following a one-year (1 July 2002¿1 July 2003) sampling campaign within the European Monitoring and Evaluation Programme, EMEP (http://www.emep.int/). The purpose of the campaign was to assess the feasibility of performing EC and OC monitoring on a regular basis and to obtain an overview of the spatial and seasonal variability on a regional scale in Europe. Analyses were performed using the thermal-optical transmission (TOT) instrument from Sunset Lab Inc., operating according to a NIOSH derived temperature program. The annual mean mass concentration of EC ranged from 0.17±0.19µgm-3 (mean ± SD) at Birkenes (Norway) to 1.83±1.32µgm-3 at Ispra (Italy). The corresponding range for OC was 1.20±1.29µgm-3 at Mace Head (Ireland) to 7.79±6.80µgm-3 at Ispra. On average, annual concentrations of EC, OC, and TC were three times higher for rural background sites in Central, Eastern and Southern Europe compared to those situated in the Northern andWestern parts of Europe. Wintertime concentrations of EC and OC were higher than those recorded during summer for the majority of the sites. Moderate to high Pearson correlation coefficients (rp) (0.50¿0.94) were observed for EC versus OC for the sites investigated. The lowest correlation coefficients were noted for the three Scandinavian sites: Aspvreten (SE), Birkenes (NO), and Virolahti (FI), and the Slovakian site Stara Lesna, and are suggested to reflect biogenic sources, wild and prescribed fires. This suggestion is supported by the fact that higher concentrations of OC are observed for summer compared to winter for these sites. For the rural background sites, total carbonaceous material accounted for 30±9% of PM10, of which 27±9% could be attributed to organic matter (OM) and 3.4±1.0% to elemental matter (EM). OM was found to be more abundant than SO2- 4 for sites reporting both parametersJRC.H.2-Climate chang

Semi-Automatic Separation Unit for Actinides at JRC-ITU and IAEA

High accuracy is required for analysis of nuclear safeguards and forensic samples. The best precision can be obtained by use of the Isotope Dilution Mass Spectrometry method. Separation of actinides is performed on chromatographic columns as sample preparation step for mass spectrometry measurements. The chromatographic separation is a time consuming process which, if performed manually, necessitates the constant presence of an operator. A semi - Automatic Separation Unit (ASU) was developed by JRC-ITU in collaboration with the IAEA as an alternative to manual separations under the EC support task to the IEA EC A-1391. It is already in use in the JRC-ITU and in cold testing for the LSS, La Hague and at SAL, IAEA. A fourth unit will be produced for the OSL Sellafield. The main features of ASU are its modular construction for simple replacement of components, minimum need for operator intervention, a light structure from materials resistant to acid environment and a remote control function over a LabView based software. A detailed report of the experience with ASU in JRC-ITU laboratories is presented.JRC.E.7-Nuclear Safeguards and Forensic

Marine aerosol chemistry gradients: elucidating primary and secondary processes and fluxes

Production mechanisms of aerosol chemical species, in terms of primary and secondary processes, were studied using vertical concentration gradient measurements at the coastal research station in Mace Head, Ireland. Total gravimetric PM1.0 mass, sea salt and water insoluble organic carbon (WIOC) concentration profiles showed a net production at the surface (i.e. primary production), while nssSO(4) and water soluble organic carbon (WSOC) concentration profiles showed a net removal at the surface. These observations indicate that WSOC was predominantly of secondary origin and that WIOC was predominantly of primary origin. Derived PM1 mass fluxes compared reasonably well with those previously obtained from an eddy covariance (EC) technique following a power law relationship with the wind speed (F(PM1) = 0.000096*U (4.23)). For cases with clear primary organic mass fluxes in the flux footprint WIOM mass fluxes ranged between 0.16 and 1.02 ng m(-2) s(-1) and WIOM/sea salt mass ratio was 0.34-3.6, in good agreement with previous measurements at Mace Head

Use of Reference Materials for Destructive Analysis at the Institute for Transuranium Elements (ITU) and the Euratom On-Site Laboratories at Sellafield and La Hague

In order to verify declared nuclear activities for safeguards purposes, high-performance analyses are a key element. The Joint Research Centre (JRC) of the European Commission runs for this purpose the Analytical Service at JRC-ITU, and on behalf of the Directorate Gerneral (DG) ENERGY (Euratom Safeguards) the two on site laboratories, at Sellafield, UK, and at La Hague, F. Destructive analyses provide highest accuracy and precision and therefore are part of the analytical techniques used. The isotopic composition and concentration of uranium and plutonium and analysis of impurities are performed using isotope dilution thermal ionisation mass spectrometry, titration, inductively coupled mass spectrometry, and carbon, nitrogen, and oxygen element content assay by fusion extraction. Reference materials play a crucial role to guarantee traceability, accuracy, and comparability of safeguard analyses. All three laboratories have different approaches in choosing the reference materials due to the local requirements. JRC-ITU produces internal reference materials complementary to certified reference material. The experience over the last 10 years is discussed with a focus on the set up of a technique for laser sealing of ampoules for long-term storage of liquid reference material.JRC.E.7-Nuclear Safeguards and Forensic

Comparative assessment of the Pu content of MOX samples by different techniques

The isotopic composition and concentration of Pu in eight "high-burn-up" mixed-oxide (MOX) fuel samples has been determined by destructive and non-destructive techniques. In addition, the U concentration and U isotopic composition was also available from the destructive techniques. The applied non-destructive techniques were gamma spectrometry, calorimetry and neutron coincidence counting, while the destructive techniques were titration, alpha spectrometry and thermal ionization mass spectrometry combined with isotope dilution. The current study describes the measurements and compares the results obtained by the mentioned techniques. Some lessons learned for the improvement of the non-destructive assay are also discussed.JRC.E.7-Nuclear Safeguards and Forensic