Special excercises

Proficiency tests

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.

Determinand Group Sample Type Exercise
Passive sampling Seawater DE13
Tetrodotoxin Shellfish DE16
Microplastics Diverse matrices DE17
Perfluorinated Alkyl Substances (PFAS) (Sea)water DE18
Pharmaceuticals (Sea)water DE19

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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.


Samples of previous proficiency tests are sold as reference materials. Available materials can be selected and ordered in our webshop. Participants are entitled to a discount.