Preliminary interlaboratory trial for ISO/DIS 12010 : determination of short chain polychlorinated alkanes (SCCP) in water

International audienceA first preliminary interlaboratory trial was planned to prepare ISO/DIS 12010: Water quality - determination of short chain polychlorinated alkanes (SCCP) in water - method using GC/MS and electron capture negative ionisation (ECNI). The task was to determine the sum of short chain polychlorinated n-alkanes with carbon chain lengths of C10-C13 and a chlorine content between 49 and 67% in water by GC-ECNI-MS and quantification by multiple linear regression described in ISO/DIS 12010 as the compulsory method. Distributed samples were obtained from a real water extract spiked with a target concentration of 0.4 micro g/mL sum of SCCP, i.e. the environmental quality target level according to the Water Framework Directive. The interlaboratory trial included the calibration, a column chromatographic clean up, a concentration step and an integration of chromatographic unresolved humps as well as the quantification with multiple linear regression. Reproducibility standard deviations between 21.5 and 22.9% were achieved by 17 participating laboratories from four countries. The method outlined no significant difference of the results between the standard solution and a real water matrix extract. On the basis of this succeeded preliminary interlaboratory trial the final interlaboratory trial for validation of ISO 12010 was prepared in autumn 2010

An interlaboratory comparison on whole water samples

The European Water Framework Directive 2000/60/EC requires monitoring of organic priority pollutants in so called “whole water” samples, i.e. in aqueous non-filtered samples that contain natural colloidal and suspended particulate matter. Colloids and suspended particles in the liquid phase constitute a challenge for sample homogeneity and stability. Within the joint research project ENV08 “Traceable measurements for monitoring critical pollutants under the European Water Framework Directive 2000/60/EC” whole water test materials were developed by spiking defined amounts of aqueous slurries of ultra-finely milled contaminated soil or sediment and aqueous solutions of humic acid into a natural mineral water matrix. This paper presents the results of an European-wide interlaboratory comparison (ILC) using this type of test materials. Target analytes were tributyl tin, polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons in the ng/L concentration range. Results of the ILC indicate that the produced materials are sufficiently homogeneous and stable to serve as samples for e.g. proficiency testing or method validation. To our knowledge, this is the first time that ready to use water materials with a defined amount of suspended particulate and colloidal matter have been applied as test samples in an interlaboratory exercise. These samples meet the requirements of the European Water Framework Directive. Previous proficiency testing schemes mainly employed filtered water samples fortified with a spike of the target analyte in a water-miscible organic solvent.JRC.D.2-Standards for Innovation and sustainable Developmen

Validation interlaboratory trial for ISO 12010 : water quality-determination of short-chain polychlorinated alkanes (SCCP) in water

International audienceA validation interlaboratory trial was carried out to prepare ISO 12010: Water quality-Determination of short-chain polychlorinated alkanes (SCCP) in water-Method using gas chromatography/mass spectrometry (GC-MS) and electron capture negative ionisation (ECNI). The task was to determine the sum of short-chain polychlorinated n-alkanes with carbon chain lengths of C-10-C-13 and a chlorine content between 49% (g/100 g) and 67% (g/100 g) in water by GC-ECNI-MS. The quantification had to be performed by multiple linear regression as described in ISO/DIS 12010, the compulsory method. Samples distributed were real river samples, and waste water spiked with a target concentration of 0.4 and 0.6 mu g/L for the sum of SCCPs, i.e. a concentration around the environmental quality target level according to the European Water Framework Directive. The different types of water samples tested were surface water with <150 mg/L suspended matter, surface water with 0.5 g/L suspended matter, and filtered waste waster. The interlaboratory trial included the extraction of the water samples, a column chromatographic clean up, a concentration step, and integration of chromatographic unresolved complex mixtures as well as the calibration and quantification by multiple linear regression. The reproducibility standard deviation of the standard concentration was 11.9%. Reproducibility standard deviations of concentrations in the three different water samples between 27.8 and 34.2% were achieved by 10-12 participating laboratories from six countries