The demonstration of competency and equivalence for the assessment of levels of contaminants and nutrients in primary foodstuffs is a priority within the 10-year strategy for the CCQM Organic Analysis WG series of Track A core comparisons. The area of low polarity analytes in high fat foods had not been covered by the OAWG for many years since the key comparison CCQM-K21 p,p'-DDT in fish oil occurring in 2000. Benzo[a]pyrene (BaP) is one of the markers for the occurrence of PAHs in foods, for which maximum residue limits are enforced in many countries. Edible oil and fats are the main source of human PAH intake. BaP may form in edible oils by pyrolytic processes, such as incomplete combustion of organic substances. Worldwide regulatory limits of BaP in edible fats and oils are from 2.0 μg/kg to 10 μg/kg. Comparable and traceable measurement results for BaP in oil are important worldwide. Thus BaP in edible oil was the model system selected to align within the OAWG strategy. 16 NMIs and DIs participated in CCQM-K146. Different methods such as liquid-liquid extraction, GPC and SPE were applied in the sample pre-treatment and HPLC-FLD, HPLC-MS/MS, and GC-MS or GC-MS/MS were applied for detection by the participants. Most participants either used their own CRMs, other NMI's CRMs or pure materials assessed in house to guarantee traceability to SI for the calibrants. One lab was excluded from the KCRV evaluation, as they did not meet the CIPM metrological traceability requirements for their calibrant. Regarding the data evaluation, five labs withdrew their results from the statistical evaluation of the KCRV for technical reasons. In line with the OAWG guidance document for KCRV estimator selection, the Hierarchical Bayes option was selected for the KCRV value, which was determined as 2.74 μg/kg with a standard uncertainty of 0.03 μg/kg. The remaining ten institutes that were included in the calculation of the consensus KCRV all agreed within their standard uncertainties. In general, the majority of CCQM-K146 participants performed very well. Therefore, this Track A Key Comparison directly illustrates the capabilities in determining mass fraction of organic compounds, with molecular mass of 100 g/mol to 500 g/mol, having low polarity pKow < -2, in mass fraction range from 0.1 μg/kg to 1000 μg/kg in a high fat, low protein, low carbohydrate food matrix. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The key comparison CCQM-K102: Polybrominated diphenyl ethers in sediment was coordinated by the JRC, Directorate F - Health, Consumers & Reference Materials, Geel (Belgium) under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Thirteen National Metrology institutes or Designated Institutes and the JRC participated. Participants were requested to report the mass fraction (on a dry mass basis) of BDE 47, 99 and 153 in the freshwater sediment study material. The sediment originated from a river in Belgium and contained PBDEs (and other pollutants) at levels commonly found in environmental samples. The comparison was designed to demonstrate participants' capability of analysing non-polar organic molecules in abiotic dried matrices (approximate range of molecular weights: 100 to 800 g/mol, polarity corresponding to pKow < −2, range of mass fraction: 1–1000 μg/kg). All participants (except one using ultrasonic extraction) applied Pressurised Liquid Extraction or Soxhlet, while the instrumental analysis was performed with GC-MS/MS, GC-MS or GC-HRMS. Isotope Dilution Mass Spectrometry approach was used for quantification (except in one case). The assigned Key Comparison Reference Values (KCRVs) were the medians of thirteen results for BDE 47 and eleven results for BDE 99 and 153, respectively. BDE 47 was assigned a KCRV of 15.60 μg/kg with a combined standard uncertainty of 0.41 μg/kg, BDE 99 was assigned a KCRV of 33.69 μg/kg with a combined standard uncertainty of 0.81 μg/kg and BDE 153 was assigned a KCRV of 6.28 μg/kg with a combined standard uncertainty of 0.28 μg/kg. The k-factor for the estimation of the expanded uncertainty of the KCRVs was chosen as k = 2. The degree of equivalence (with the KCRV) and its uncertainty were calculated for each result. Most of the participants to CCQM-K102 were able to demonstrate or confirm their capabilities in the analysis of non-polar organic molecules in abiotic dried matrices. Throughout the study it became clear that matrix interferences can influence the accurate quantification of the PBDEs, if the analytical methodology applied is not appropriately adapted and optimised. This comparison shows that quantification of PBDEs at the μg/kg low-middle range in a challenging environmental abiotic dried matrix can be achieved with relative expanded uncertainties below 15 % (more than 70 % of participating laboratories), well in line with the best measurement performances in the environmental analysis field. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The issues of the functioning of the BIPM and the corresponding committee -CCQM, coordinating the work on the comparisons of national standards in the field of organic analysis have considered in this article. The structure and tasks of the CCQM have described and the measurement categories for the amount of substance have given. The main aspects of the OAWG activities have discussed and the issues of systematization and separation of comparisons in the field of organic analysis have discussed in detail and various approaches to the development of competence areas based on key comparisons have set out. The fundamental importance of pure organic substances in providing metrological traceability in organic analysis has highlighted. The key role of the State Primary Standard GET 208 in terms of confirming the equivalence of the calibration and measurement capabilities (CMC) of Russia at the international level has been determined.

Solutions of organic analytes of known mass fraction are typically used to calibrate the measurement processes used to determine these compounds in matrix samples. Appropriate value assignments and uncertainty calculations for calibration solutions are critical for accurate measurements. Evidence of successful participation in formal, relevant international comparisons is needed to document measurement capability claims (CMCs) made by national metrology institutes (NMIs) and designated institutes (DIs). To enable NMIs and DIs to update or establish their claims, in 2015 the Organic Analysis Working Group (OAWG) sponsored CCQM-K131 “Low-Polarity Analytes in a Multicomponent Organic Solution: Polycyclic Aromatic Hydrocarbons (PAHs) in Acetonitrile”. Polycyclic aromatic hydrocarbons (PAHs) result from combustion sources and are ubiquitous in environmental samples. The PAH congeners, benz[a]anthracene (BaA), benzo[a]pyrene (BaP), and naphthalene (Nap) were selected as the target analytes for CCQM-K131. These targets span the volatility range of PAHs found in environmental samples and include potentially problematic chromatographic separations. Nineteen NMIs participated in CCQM-K131. The consensus summary mass fractions for the three PAHs are in the range of (5 to 25) μg/g with relative standard deviations of (2.5 to 3.5) %. Successful participation in CCQM-K131 demonstrates the following measurement capabilities in determining mass fraction of organic compounds of moderate to insignificant volatility, molar mass of 100 g/mol up to 500 g/mol, and polarity pKow < −2 in a multicomponent organic solution ranging in mass fraction from 100 ng/g to 100 μg/g: (1) value assignment of primary reference standards (if in-house purity assessment carried out), (2) value assignment of single and/or multi-component organic solutions, and (3) separation and quantification using gas chromatography or liquid chromatography. KEY WORDS FOR SEARCH benz[a]anthracene (BaA), benzo[a]pyrene (BaP), gas chromatography(GC), isotope dilution (ID), liquid chromatography (LC), mass spectrometry (MS), naphthalene (Nap), organic calibration solution, polycyclic aromatic hydrocarbon (PAH) Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).