Novel surface water reference materials used in two laboratory intercomparisons

surface water
From concept to reality: novel surface water reference materials used in two laboratory intercomparisons © EU

Scientists from 11 research organisations – including the JRC –  have demonstrated the quality and applicability of whole water reference materials for the determination of organic contaminants in natural waters. This work is supporting the implementation of the European Water Framework Directive.

The European Water Framework Directive 2000/60/EC and amending Directives require the monitoring of organic priority pollutants in so-called whole water samples. The latter are aqueous non-filtered samples containing natural colloidal and suspended particulate matter. It needs to be stressed that such water constituents are posing a great challenge for the analysis as well as for reference material preparation due to potential homogeneity and stability problems.

Therefore, the JRC developed three novel surface-water test materials for which the uncertainties associated with the stability and homogeneity of 15 target parameters (polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyl tin (TBT)) were evaluated. In order to be of any meaningful use in the intercomparisons, reference materials (RMs) have to be sufficiently stable and homogeneous during their intended lifetime. These two characteristics ensure that no significant degradation of the priority substances occurs during storage and transport of the RMs and that the target analyte concentrations have a high degree of equivalence between sample units. Only if such characteristics can be achieved with low uncertainties, RMs are useful as a means to ensure the quality and comparability of the measurement results provided by testing laboratories across Europe.

The suitability of the three new candidate RMs was proven in a European-wide interlaboratory comparison study.  In addition, these reference materials were used to validate candidate CEN standard methods also confirming their suitability and high quality.

Read more in: S. Elordui-Zapatarietxe et al.: “Preparation and evaluation of sufficiently homogeneous and stable reference materials for priority hazardous substances in whole water”, Accred. Qual. Assur. 21 (2016) 113-120, doi: 10.1007/s00769-015-1189-1.

J. Richter et al.: “An interlaboratory comparison on whole water samples“, Accred. Qual. Assur. 21 (2016) 121-129, doi:10.1007/s00769-015-1190-8.

JRC publication: “An interlaboratory comparison on whole water samples