CIPM MRA COMPARISON REPORTS

Polycyclic aromatic hydrocarbons (PAHs) are hydrophobic and carcinogenic compounds that accumulate in sediments. They originate from pyrolytic, petrogenic, and diagenetic sources. The accurate measurement of PAHs in sediments is essential for environmental monitoring and for implementing regulatory frameworks such as Sediment Quality Guidelines, given their persistence, toxicity, and role as key pollution indicators.
To enable national metrology institutes (NMIs) and designated institutes (DIs) to update or establish their measurement capability claims (CMC), the CCQM Organic Analysis Working Group (OAWG) sponsored the key comparison CCQM-K184 in 2023. This study was coordinated by the National Institute of Metrology (NIM) of China on behalf of the OAWG, under the auspices of the Consultative Committee for Amount of Substance (CCQM), and was conducted alongside a parallel pilot study (CCQM-P235). Seventeen NMIs and DIs participated in the comparison CCQM-K184, titled "Polycyclic Aromatic Hydrocarbons (PAHs) in Sediment".
Participants were required to determine the mass fractions of fluoranthene, benzo[a]pyrene, benzo[ghi]perylene, and optionally phenanthrene in a river sediment sample collected from a tributary of the Taizi River in China. Successful participation in CCQM-K184 demonstrates a laboratory’s competence in determining the mass fraction of organic compounds with a molecular mass of 170 g/mol to 500 g/mol and low polarity (pKow < -2), in the range of 100 µg/kg to 1,000,000 µg/kg, in an abiotic dried matrix such as sediment. The demonstrated capabilities encompass: (i) value assignment of primary reference standards; (ii) value assignment of calibration solutions; (iii) extraction of analytes of interest from the matrix; (iv) clean-up and separation of target analytes from interfering matrix or extract components; and (v) separation and quantification using techniques such as GC-IDMS, GC-IDMS/MS, or HPLC-FLD.