Certification of the Mass Fractions of Vitamins in Whole Milk Powder - Certified Reference Material ERM®-BD600

This report describes the production of the reference material ERM-BD600, a whole milk powder certified for the mass fractions of water- and fat-soluble vitamins. All the required steps during the production were conducted according to ISO Guides 34 and 35 [1,2] to ensure the high quality of the final product, including matrix material processing, homogeneity and stability studies and value assignment. The matrix material, a spray dried whole milk powder, was packed into sachets containing approximately 100 g of powder, and stored at -30 ºC. Dedicated studies confirmed the homogeneity and stability of the vitamins in the milk powder under the conditions evaluated. The characterisation of the material, organised and coordinated by IRMM, was done by an inter-laboratory comparison. The certified and indicative values were obtained as the unweighted mean of the laboratory means of the accepted sets of results for each analyte, and the expanded uncertainty associated (k = 2) includes contributions from the homogeneity, the long term stability and the characterisation of the material.JRC.D.2-Reference material

CERTIFICATION OF THE MASS FRACTION OF PERFLUORALKYL SUBSTANCES (PFASs) IN FISH TISSUE (PIKE-PERCH): IRMM-427

This report describes the production of IRMM-427, a fish material certified for the mass fraction of perfluoroalkyl substances (PFASs). The material was produced following ISO Guide 34:2009. The starting material for the CRM is naturally contaminated pike-perch fillets originating from the rivers Nieuwe Merwede and Amer in the Netherlands. After converting the tissue into a paste, the material was sterilized by autoclavation at 120 °C and the jars stored at 18 °C. 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 in most cases adhering to ISO/IEC 17025:2005. 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, instability and 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 CRM is available in glass jars containing approximately 35 g of fish paste. The minimum amount of sample to be used is 1 g.JRC.D.5-Standards for Food Bioscienc

The certification of the mass concentration of perfluoroalkyl substances (PFASs) in water: IRMM-428

This report describes the production of IRMM-428, a water material certified for the mass fraction of perfluoroalkyl substances (PFASs). The material was produced following ISO Guide 34:2009. The starting material for the CRM is tap drinking water, collected in Nieuwegein, the Netherlands. The material was spiked with a mixture of PFASs, bottled and sterilised by gamma irradiation, before storage at -20 ºC . 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 in most cases 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, instability and 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 CRM is available in high density polyethylene (HDPE) bottles containing 410 mL of water material. The minimum amount of sample to be used is 100 mL.JRC.D.5-Standards for Food Bioscienc

IMEP-42: Determination of PFASs in fish

The Institute for Reference Materials and Measurements of the Joint Research Centre, a Directorate General of the European Commission (EC-JRC-IRMM) operates the International Measurement Evaluation Programme (IMEP). It organises interlaboratory comparisons (ILC's) in support to European Union (EU) policies. This report presents the results of a proficiency test (PT), IMEP-42, on the determination of perfluoroalkyl substances (PFASs) in fish tissue. The exercise was organised in support to the Commission Recommendation 2010/161/EU on the monitoring of perfluoroalkylated substances in food and the Water Framework Directive 2000/60/EC. Seventeen participants from thirteen countries registered to the exercise and all of them reported results. The test item was fish tissue (pike-perch) containing perfluoroalkyl carboxylates as perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA) or perfluorotetradecanoic acid (PFTeDA); perfluoroalkyl sulfonates as perfluorohexanesulfonate (PFHxS), linear perfluorooctane sulfonate (L-PFOS) or branched perfluorooctane sulfonate (br-PFOS); and, perfluoroalkyl sulphonamides as perfluorooctane sulphonamide (FOSA). The test item was a candidate certified reference material (CRM) produced by IRMM under ISO Guide 34 accreditation and in line with ISO Guide 35. Laboratories with demonstrated experience in the field provided results to establish the assigned values (Xref). The standard uncertainties associated to the assigned values (uref) were calculated according to the ISO Guide 35 by combining the uncertainty of the characterisation (uchar) with a contribution for homogeneity (ubb) and for stability (ust). Laboratory results were rated with z- and zeta (ζ-) scores in accordance with ISO 13528. The standard deviation for the proficiency assessment, σ ̂, for all elements was set at 25 % of the respective assigned value. The overall performance in this PT was good even though analyte dependent. High rates (78% - 100%) of satisfactory performances expressed as z-scores ≤ 2 were obtained for L-PFOS, PFDA, PFUnDA, PFDoDA, tot-PFOS and FOSA while the lowest rates of satisfactory performances (50%) were obtained for br-PFOS and PFTrDA. Many "less than X" values were reported for the three PFASs that could not be scored due to the high uncertainty on the assigned value (PFNA, PFTeDA and PFHxS). The results in this PT showed that the sensitivities of the methods used by the participants were fit for the purpose of measuring the legal limits set in legislation.JRC.D.5-Standards for Food Bioscienc

Certification of the Mass Fraction of Polycyclic Aromatic Hydrocarbons (PAHs) in Toluene - Certified Reference Materials ERM®-AC213

This report describes the preparation of a calibration solution of polycyclic aromatic hydrocarbons (PAHs) (ERM-AC213) containing benzo[a]pyrene, benz[a]anthracene, cyclopenta[cd]pyrene, chrysene, benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, dibenz[a,h]anthracene, dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, indeno[1,2,3-cd]pyrene, 5-methylchrysene and benzo[c]fluorene and the certification of their content (mass fraction) in the solution. The preparation of the calibrant, homogeneity and stability studies and confirmation measurements with a discussion of the results are described hereafter. Uncertainties were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) [1] and include uncertainties due to the processing, purity assessment and possible instability.JRC.DG.D.2-Reference material

Caracterización de metalotioneínas y moléculas afines

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Analítica. Fecha de lectura: 05-04-200