Validation of a GC-IDMS method for the metrologically traceable quantification of selected FAMEs in biodiesel

Current methods for the analysis of fatty acid methyl esters (FAMEs) in rapeseed oil based biodiesel refer to operationally defined measurands, which is a practical solution for routine analysis. In this paper, a new method for the SI-traceable quantification of selected FAMEs in biodiesel and its validation are described. This method has the potential to be a reference method for applications requiring structurally defined measurands and traceability to the SI as it allows direct comparisons to well characterised calibrants through the use of isotopically labelled analogues of the analytes as well as establishing of a full uncertainty budget. The method is based on gas chromatography-isotope dilution mass spectrometry. Its performance is demonstrated through its implementation and validation in two independent laboratories and is shown to provide reliable and traceable results for selected FAMEs in biodiesel test samples.JRC.D.2-Standards for Innovation and sustainable Developmen

Comparison of the Seed Oils of Ferulago trachycarpa Boiss. Different Localities with Respect to Fatty Acids

The fatty acid composition of the seed oil of Ferulago trachycarpa Boiss., collected from two different localities (Balikesir-Edremit and Konya-Seydisehir), was analyzed for derived methyl esters of their fatty acids by capillary gas chromatography-mass spectrometry (GC-MS). Seventeen components representing 98.7 % of Balikesir sample and 98.6 % of Konya sample of F. trachycarpa seed oils were identified. GC-MS data showed that the main fatty acids were 9-octadeceneoic acid (68.1 and 73.6 %), 9,12-octadecadienoic acid (23.0 and 18.0 %), 9-hexadeceneoic acid (4.1 and 3.5 %) and 11-octadecenoic acid (2.0 and 1.8 %) in both oils, respectively. Unsaturated fatty acids were found as high as 97.7 and 97.4 %, while the percentage of the saturated fatty acids was found as low as 1.0 and 1.2 % in both seed oils, respectively

Joint Research Project env08 “Traceable measurements for monitoring critical pollutants under the European Water Framework Directive (WFD) 2000/60/EC”

The Joint Research Project ENV08 “Traceable measurements for monitoring critical pollutants under the European Water Framework Directive (WFD) 2000/60/EC” is a multi-partner trans-national project within the targeted call “Environment” of the European Metrology Research Programme (EMRP). The EMRP represents a metrology-focused European programme of coordinated research and development that facilitates closer integration of national research programmes. ENV08 deals with the grand challenges for multidisciplinary metrology in environment meeting “the most urgent industrial and societal needs” as stated in the EMRP Outline 2008. The project aims to provide reference methods capable of analysing priority hazardous substances specified in the WFD at the proposed low environmental quality standard concentrations in the body of ground, surface and coastal waters. In addition, ENV08 will answer the need for accuracy and comparability of measurements for the end users capabilities assessment by developing concepts for reference materials. ENV08 is coordinated by BAM (Germany) and involves 14 European institutes. Five institutes work on the development of a validated measurement procedure for Polycyclic Aromatic Hydrocarbons (PAH) in whole water samples at a concentration level required by the EU Water Framework Directive (WFD)

Final report on key comparison CCQM-K55.c (L-(+)-Valine): Characterization of organic substances for chemical purity

Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM K55.c, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2012. Twenty National Measurement Institutes or Designated Institutes and the BIPM participated. Participants were required to assign the mass fraction of valine present as the main component in the comparison sample for CCQM-K55.c. The comparison samples were prepared from analytical grade L-valine purchased from a commercial supplier and used as provided without further treatment or purification. Valine was selected to be representative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of low structural complexity [molecular weight range 100–300] and high polarity (pKOW > −2). The KCRV for the valine content of the material was 992.0 mg/g with a combined standard uncertainty of 0.3 mg/g. The key comparison reference value (KCRV) was assigned by combination of KCRVs assigned from participant results for each orthogonal impurity class. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 1 mg/g to 6 mg/g when using mass balance based approaches alone, 2 mg/g to 7 mg/g using quantitative 1H NMR (qNMR) based approaches and from 1 mg/g to 2.5 mg/g when a result obtained by a mass balance method was combined with a separate qNMR result. The material provided several analytical challenges. In addition to the need to identify and quantify various related amino acid impurities including leucine, isoleucine, alanine and α-amino butyrate, care was required to select appropriate conditions for performing Karl Fischer titration assay for water content to avoid bias due to in situ formation of water by self-condensation under the assay conditions. It also proved to be a challenging compound for purity assignment by qNMR techniques. There was overall excellent agreement between participants in the identification and the quantification of the total and individual related structure impurities, water content, residual solvent and total non-volatile content of the sample. Appropriate technical justifications were developed to rationalise observed discrepancies in the limited cases where methodology differences led to inconsistent results. The comparison demonstrated that to perform a qNMR purity assignment the selection of appropriate parameters and an understanding of their potential influence on the assigned value is critical for reliable implementation of the method, particularly when one or more of the peaks to be quantified consist of complex multiplet signals.JRC.D.2-Standards for Innovation and sustainable Developmen