CERTIFICATION REPORT: The certification of water-soluble ions in a fine dust (PM2,5-like) material: ERM-CZ110
This report describes the production of ERM®-CZ110, which is a fine particulate matter (PM2,5-like) material certified for the mass fraction of water-soluble ions (Na+, K+, Ca2+, Mg2+, Cl-, NO3- and SO42-) extracted according to CEN/TR 16269:2011 or EN 16913:2017. An indicative value for the mass fraction of NH4+ (extracted according CEN/TR 16269:2011 or EN 16913:2017) and informative values for the mass fraction of Na, K, Ca and Mg after complete digestion of the sample are also reported. This material was produced following ISO 17034:2016 [[i]] and is certified in accordance with ISO Guide 35:2017 [2].
The Certified Reference Material (CRM) is a particulate matter collected from a road tunnel in Poland. The material was first sieved and jet-milled to reduce its particles’ size. Then, it was suspended in a solution, spiked with appropriate levels of the desired ions and siphoned off to allow collection of smaller and lighter particles. Finally, the solution was dropwise shock-frozen in liquid nitrogen and freeze-dried. The resulted fine dust (PM2,5-like size) was collected into vials under an inert atmosphere of nitrogen.
Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2017 [[ii]]. Within-unit homogeneity was quantified to determine the minimum sample intake.
The material was characterised by an inter-laboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025:2017 [[iii]] or with documented evidence of technical competence related to the work in question. Technically invalid results were removed but no outlier was eliminated on statistical grounds only.
Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [[iv]] and include uncertainties related to possible inhomogeneity, instability and characterisation.
The analytical behaviour was checked by comparison of ERM-CZ110 with real environmental PM2,5. The extractability of ions is the same as for authentic air-sampled PM2,5.
The material is intended for the quality control and assessment of method performance. As with any reference material, it can be used for establishing control charts or validation studies. The CRM is available in glass vials containing at least 150 mg of powder which were sealed under an atmosphere of nitrogen. Glass vials are contained in thermally-sealed aluminium sachets. The minimum amount of sample to be used is 5 mg.
EMMA Giovanni;
SANTORO Anna;
SNELL James;
CHAROUD-GOT Jean;
HELD Andrea;
2020-10-26
Publications Office of the European Union
JRC121753
978-92-76-21516-5 (online),
1831-9424 (online),
EUR 30359 EN,
OP KJ-NA-30359-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC121753,
10.2760/324965 (online),
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