Second EC-JRC Aromatic Compounds Intercomparison with Automatic Analyzer

This report presents the results of the second intercomparison for BTEX automatic analysers carried out by the JRC on the 17-19 June 2008. Seven national reference laboratories participated in this exercise. Six concentrations levels were tested during the intercomparison, ranging from circa 3 to 50 µg/m3, for benzene. With respect to the first intercomparison carried out in 2005, the reference value was assigned by ERLAP and the exercise was evaluated according to ISO 13528 methodologies for the evaluation of interlaboratory proficiency assessment and the recommendation of the protocol N37 of the AQUILA network. Participating laboratories are identified as requested by the AQUILA for further actions. In general, the results of the exercise show no changes in the performance of the method with respect to the previous exercise. The robustness of the method is still an issue in particular for benzene. This is reflected in a relatively high interlaboratory reproducibility standard deviation. As a consequence, the criterion for the standard deviation for proficiency assessment proposed in the AQUILA protocol seems to be very restrictive for the current performance of the methodology, this may require future harmonisation actions in the implemented methodology.JRC.H.4-Transport and air qualit

Comparison of established and emerging biodosimetry assays

Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3-0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5-4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools

The evaluation of the interlaboratory comparison exercise for SO2, CO, O3, NO and NO2 14-17 June 2010

From the 14th to the 17th of June 2010 in Ispra (IT), 9 Laboratories of AQUILA (Network of European Air Quality Reference Laboratories) met at an interlaboratory comparison exercise to evaluate their proficiency in the analysis of inorganic gaseous pollutants covered by European Directive about air quality (SO2, CO, NO, NO2 and O3). The proficiency evaluation, where each participant’s bias was compared to two criteria, provides information on the current situation and capabilities to the European Commission and can be used by participants in their quality control system. On the basis of criteria imposed by the European Commission, 85% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. Another 12% of the results had good measured values, but the reported uncertainties were either too high (8%) or too small (4%). Comparability of results among AQUILA participants at the highest concentration level, excluding outliers, is acceptable in NO, CO and O3 measurements while NO2 and SO2 measurement methods showed less satisfactory results.JRC.H.2-Climate change and air qualit

Report of the interlaboratory comparison organised by the EU Reference for Laboratory Food Contact Material - ILC02 2009- Bisphenol A in 50% aqueous ethanol (milk simulant): Laboratory performance and precision criteria of a harmonised method

The Institute for Health and Consumer Protection (IHCP) of the European Commission¿s Directorate-General Joint Research Centre hosts the Community Reference Laboratory for Food Contact Materials (EURL-FCM). One of its core tasks is to organize interlaboratory comparisons (ILCs) among appointed National Reference Laboratories (NRLs). This report presents the results of the second ILC exercise of the EURL-FCM for the year 2009, which focused on the determination of Bisphenol A (BPA) in 50% aqueous ethanol as a food simulant for milk. The general aim was to develop and perform the validation of a method for the analysis of Bisphenol A as model substance for a polycarbonate (PC), since it is a material that has typically been used as baby bottles and therefore typically in contact with mostly milk-type products. The strategy rose from the implementation of the new milk simulant 50% Ethanol (EtOH) in Commission Directive 2007/19/EC that current CEN standards for specific migration have not addressed yet. Four 50% ethanol solutions containing different concentrations of Bisphenol A were provided for analysis encompassing concentrations of relevance to exposure determination and compliance determination. The homogeneity and stability studies were performed by the EURL-FCM laboratory. Standard operating procedures (SOPs) for the two approaches were also written. There were 31 participants from twenty-five countries to whom samples were dispatched and 26 of which submitted results. The results of analyses were received and statistically interpreted. The assigned values were obtained as a consensus values after applying the robust statistics to the results obtained from the participants. Laboratory results were rated with z-scores in accordance with ISO 13528 [1]. Standard deviations for ILC comparison (also called target standard deviations) were set based on Horwitz equation and Horrat ratio 0.5. The results and preliminary report were discussed in the plenary of December 2009. The participation of the laboratories was regarded as satisfactory for the aim of the precision experiment with regards of the numbers of received results. As a conclusion of the precision exercise on the quantification of Bisphenol A in the new milk simulant 50% ethanol, this ILC showed that the validation of the method based on HPLC-FLD according to the description based mostly on the previous CEN standard TS 13130-13 was successful. The precision that can be suggested were of 15% reproducibility SD and 6% repeatability SD for the 0.0067 mg/kg level, 10% reproducibility SD and 4% repeatability SD for the 0.0.21 mg/kg level, 6% reproducibility SD and 2% repeatability SD for the 0.0.75 mg/kg level, 6% reproducibility SD and 0.2% repeatability SD for the 0.56 mg/kg level. With respect to the scarcity of data previously available in the validation performed as reported in the CEN standard TS 13130-13 (issued version of 2005), this validation also provides a great breadth of valuable detailed and traceable raw data, which should prove extremely relevant for the creation of an extension of the standard from CEN.JRC.DG.I.2-Chemical assessment and testin

Report of the Second Interlaboratory Comparison Organised by the Community Reference Laboratory for Heavy Metals in Feed and Food: Total Cd, Pb and Hg in Mineral Water

The Institute for Reference Materials and Measurements (IRMM) of the European Commission's Directorate-General Joint Research Centre holds the Community Reference Laboratory for Heavy Metals in Feed and Food (CRL-HM). One of the core tasks is to organise interlaboratory comparisons (ILCs) among appointed National Reference Laboratories (NRLs). This report presents the results of the second ILC of the CRL-HM which focused on the determination of the total Cd, Pb and Hg content in mineral water. The test material used in this exercise was a commercial mineral water purchased in Belgium at a local supermarket. The material was spiked with Cd, Pb and Hg, rebottled and dispatched by the Reference Material Unit of the IRMM. The samples were dispatched on the first half of May 2007. Each participant received two sets of samples containing one bottle per set. Each bottle contained approximately 100 mL of test material. Twenty participants from 17 countries registered to the exercise of which 20 submitted results for Cd and Pb and 19 for Hg. The assigned values were those obtained from the gravimetric measurements used to spike the material. The homogeneity and stability studies were subcontracted to the University of Natural Resources and Applied Life Sciences (BOKU) in Vienna. The uncertainty of the assigned values was calculated combining the uncertainty of the spiking procedure with a contribution for the between-bottle homogeneity and for long-term stability of the test material. Participants were invited to report the uncertainty on their measurements. This was done by all them. Laboratory results were rated with z and zeta scores in accordance with ISO 135281. Standard deviation for proficiency assessment (also called target standard deviation) for Cd, Pb and Hg was 10% of the assigned value.JRC.D.4-Isotope measurement

IMEP-26: Determination of Brominated Flame Retardants in Plastic

This report presents the results of an interlaboratory comparison (ILC) which focussed on the determination of total bromine, total sum of polybrominated biphenyls (PBB), total sum of polybrominated diphenylethers (PBDE), brominated diphenylethers (BDE-47, BDE-99, BDE-183 and BDE-209) and decabrominated biphenyl (BB-209) in plastic. The test material used in this exercise was the Quality Control material (IRMM-310) from the Institute for Reference Materials and Measurements (IRMM) a poly(ethyleneterephthalate) (PET) granulated that has been fortified with commercially available technical mixtures of polybrominated diphenylethers and polybrominated biphenyls. The material was relabelled to avoid its recognition. Twenty-five laboratories from 15 countries registered to the exercise, from which 23 reported results. The informative values provided by the IRMM-310 material information sheet were taken as the assigned values and their associated uncertainties for all measurands. Studies to asses the adequacy of the selected test material regarding its homogeneity for all the selected measurands were undertaken Participants were invited to report the uncertainty of their measurements. Laboratory results were rated with z- and ζ-scores (zeta-scores) in accordance with ISO 13528. The standard deviation for proficiency assessment was fixed to 25 % of the respective assigned value by the advisory board of this ILC. The outcome of the exercise was illustrating quite well the difficulties laboratories do have to provide consistent values for the investigated measurands; the share of satisfactory z-scores ranged between 61 and 88 %. There was a clear tendency to underestimate most of the measurands. The most influencing variables, leading to the observed variability and lack of trueness, were investigated.JRC.DG.D.6-Food Safety and Qualit

Ejercicio interlaboratorio de bioensayos marinos para la evaluación de la calidad ambiental de sedimentos costeros. IV. Ensayo de toxicidad sobre sedimento con crustáceos anfípodos

9 páginas, 2 figuras, 3 tablas.[EN] Interlaboratory variability was studied for the bioassay using crustacean amphipods. Nine series of data were obtained from different laboratories using four different species (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum and Microdeutopus gryllotalpa), all previously used for sediment toxicity assessment in Spain. Results were studied for interlaboratory variability and according to different confounding factors. The coefficients of variation were similar to those previously reported for this bioassay and sample classification was homogeneous among the laboratories that successfully completed the exercise. No significant tendencies related to test species were identified and it seems that the factor most critically affecting test results and the classification of samples is storage time before testing.[ES] Se estudió la precisión interlaboratorio del bioensayo con crustáceos anfípodos. Se recogieron nueve series de datos procedentes de distintos laboratorios europeos y de cuatro especies distintas (Ampelisca brevicornis, Corophium volutator, Corophium multisetosum y Microdeutopus gryllotalpa), todas ellas usadas previamente para la caracterización de la toxicidad de sedimentos en España. Esos resultados se estudiaron para evaluar la variabilidad interlaboratorio de acuerdo a las diferentes especies y los distintos tiempos de almacenamiento de las muestras antes del ensayo. Los resultados mostraron coeficientes de variación similares a los encontrados en estudios previos y permitieron una clasificación homogénea de las muestras entre los laboratorios que completaron el ejercicio con éxito. No se identificaron tendencias significativas debidas al uso de distintas especies y, al parecer, el factor que puede afectar más críticamente la clasificación de las muestras y, por lo tanto, el uso de los resultados para la toma de decisiones, es el tiempo de almacenamiento de los sedimentos previamente al desarrollo del ensayo.This study was carried out under a joint research project between CEDEX and the University of Cádiz. Part of the work was funded by the Spanish Ministry of Science and Technology REN2002_01699/TECNO). The first author was supported by a grant (FPI) from the Spanish Ministry of Education and Science.Peer reviewe