Special excercises
For emerging pollutants/determinands or in case of poor comparability among laboratories analytical methodology may need to be refined. On request WEPAL-QUASIMEME offers development exercises to develop and improve the methodology, that may result in a new proficiency test scheme on a regular base.
Workshops that focus on specific problems and to discuss achievements or corrective actions can be part of these development exercises.
Participation is open to all laboratories worldwide, however, some determinands are only suitable for local laboratories as analysis needs to be performed on fresh samples. Preservation of samples is not applicable for all types of determinands.
The normal validated methods and procedures of each laboratory should be used to analyse the test materials. Laboratories are requested to fill in method information codes (MIC) for each determinand. This allows laboratories to review the range and similarity of the methodologies used.
Join the Global Microplastics Interlaboratory Study – Round 2026
Help improve the comparability of microplastics analysis by participating in Development Exercise DE17. Laboratories worldwide are invited to analyse shared water and/or sand samples using their own particle-counting methods, contributing to the development of more reliable and harmonised analytical approaches.
Organised by VU Amsterdam, the Norwegian Institute for Water Research (NIVA) and WEPAL-QUASIMEME, with support from the NORMAN Working Group on Nano- and Micro-scale Particulate Contaminants.
What to expect
Development Exercise DE17 focuses on the development and comparison of particle-counting methods for microplastics analysis. Participating laboratories will analyse a shared set of water and/or sand samples using their own analytical approach, enabling benchmarking and comparison of results across laboratories.
- Target: Enumeration of microplastic particles in the 20–500 µm size range.
- Samples: Three water samples and/or three sand samples, including two spiked samples and one blank for each matrix.
- Who can participate? Laboratories using any particle-counting method.
- Registration deadline: 15 September 2026
- Sample distribution: 26–28 October 2026.
- Results submission deadline: 1 March 2027.
- Reporting: Draft report in April 2027, final report in June 2027, followed by an online results webinar.
- Participation fee: €950 for the combined water and sand programme or €600 for either programme separately.
- Determinand Group
Passive sampling
Sample TypeFreshwater
ExerciseDE13
General Information
- Samples are mainly prepared from local Dutch sources.
- The preserved samples are stable for the period of the test when stored properly.
- All samples are prepared in bulk and tested for its homogeneity where relevant.
- Use your normal validated methods and procedures to analyse the test materials.
- New determinands can be added to these programs on request.
- Reports contain all data reported under strict confidentiality, including Z-score plots and method information of methods used.
Determinands
The list below shows typical determinands for the development excercises.
| Analyte group | Typical analytes | Excercise |
|---|---|---|
Passive samplers | HCB, HCBD, PCBs, PAHs, brominated flame retardants | |
Microplastics | Total number of particles, Total mass of plastic particles | |
Perfluorinated alkyl substances (PFAS) | PFOS, PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoA, PFTrDA, PFTeDA, L-PFBS, L-PFHxS, L-PFHpS, PFOSA, PFDS, PFODA, GenX, F-53B, PFBSA, PFHxSA, NMeFOSAA and NEtFOSAA | |
Pharmaceuticals | Diclofenac, Carbamazepine, Ibuprofen, Azithromycin, Clarithromycin and Erythromycin |
- Analyte group
Passive samplers
Typical analytesHCB, HCBD, PCBs, PAHs, brominated flame retardants
Excercise - Analyte group
Microplastics
Typical analytesTotal number of particles, Total mass of plastic particles
Excercise - Analyte group
Perfluorinated alkyl substances (PFAS)
Typical analytesPFOS, PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoA, PFTrDA, PFTeDA, L-PFBS, L-PFHxS, L-PFHpS, PFOSA, PFDS, PFODA, GenX, F-53B, PFBSA, PFHxSA, NMeFOSAA and NEtFOSAA
Excercise - Analyte group
Pharmaceuticals
Typical analytesDiclofenac, Carbamazepine, Ibuprofen, Azithromycin, Clarithromycin and Erythromycin
Excercise