The aim of this work package is to evaluate the fitness for purpose of the MS-based and Effect-based methods developed for the determination of selected estrogenic substances in surface water samples.
If these 3 estrogenic analytes of choice become priority substances the maximum method detection limit (MDL) values will become EQS. As required by the Directive 2009/90/EC (QA/QC Directive), the LOQ not exceeding 30 % of the relevant EQS with a measurement uncertainty ≤50 % at EQS. Here the uncertainty is regulated by the GUM approach and ISO 11352 respectively.
Task 3.1 is aimed at the preparation of an aqueous reference material (RM) which reproduces the properties of real water samples as close as possible, i.e. including suspended particulate matter. The outcomes Task 1.1 and Task 1.3, particularly stability, will be taken into account in selecting the suitable real matrix to be used, and in the in planning and production of the RMs (e.g. matrix treatment, selection of suitable containers, interferences, and stability of the 3 target compounds). Homogeneity and stability studies of the candidate RM will be carried out according to ISO Guide 35.
The reference material will be used in an interlaboratory comparison (ILC) (Task 3.2) between the project partners. Testing laboratories that are collaborators or stakeholders of the project will also be invited to join the ILC. The results of the ILC will be used to verify the application of the developed MS and effect-based measurement methods in different laboratories and to assess repeatability and reproducibility (Task 3.3). The knowledge on preparation methods (loading a model-SPM and humic acid (HA) to water samples in a controlled manner) for aqueous whole water reference materials gained in JRP ENV08 WFD will be applied in the preparation of RM and ILC.

• Task 3.1: Feasibility and preparation of a synthetic real-matrix reference material for the 5 selected estrogens
• Task 3.2: Interlaboratory comparison of chemical MS-based and EBMs
• Task 3.3: Demonstration of method validity and equivalency of measurements

WP leader: Dr. Noora Perkola, SYKE, contact: Noora.Perkola@ymparisto.fi